Protective coatings. Fastener coating conventions

8. Designation of methods for processing the base metal

Processing method base metal	Designation	Processing method base metal	Designation
Brushing		Chemical polishing
Punching		Electrochemical polishing
Shading		Electrochemical polishing
Vibration rolling		"Snow" etching
Diamond processing		Pearl-like finish
Satin		Drawing arched lines	dl
Matting	mt	Hairline application
Mechanical polishing		Passivation

9. Designation of coating methods

Method of obtaining coverings	Designation	Method of obtaining coverings	Designation
Cathodic reduction		Condensing (vacuum)
Anodic oxidation *	An	Contact
Chemical		Contact-mechanical
		Cathodic sputtering
Diffusion		Firing
Thermal spraying	According to GOST 9.304-87	Enameled
Thermal decomposition **		Cladding

The coating material, consisting of metal, is designated by symbols in the form of one or two letters included in the Russian name of the corresponding metal (Table 10).

10. Designation of the coating material, consisting of metal

Metal coverings	Designation	Metal coverings	Designation
Aluminum		Palladium

Tungsten

The coating material consisting of an alloy is denoted by the symbols of the components that make up the alloy, separating them with a hyphen, and in parentheses indicate the maximum mass fraction of the first or first and second (in the case of a three-component alloy) components in the alloy, separating them with a semicolon.
Examples of designation: coating with a copper-zinc alloy with a mass fraction of copper 50-60% and zinc 40-50%

Coating with copper-tin-lead alloy with a mass fraction of copper 70-78%, tin 10-18%, lead 4-20%

M-O-C (78; 18).

11. Designation of nickel and chrome coatings

Coating name	Designation
Coating name	abbreviated
Nickel obtained brilliant made of electrolyte with gloss forming additives containing more than 0.04% sulfur
Nickel matt or semi-gloss, containing less than 0.05% sulfur; test elongation tensile not less than 8%
Nickel:

two-layer (duplex)
three-layer (triplex)		Npb. Ns. NB
two-layer composite - nickel-force *
two-layer composite
three-layer composite		Npb. Ns. Ns
Chrome:

porous
microcracked
microporous
"Dairy"
double layer		Khmol. X. tv

If necessary, technical requirements the drawing indicate the symbol of the chemical element or the formula chemical compound used as a co-precipitated substance.
Note. It is allowed to use abbreviated designations and indicate the total thickness of the coating.
In the designation of the coating material with an alloy (Table 12), if necessary, it is allowed to indicate the minimum and maximum mass fractions of the components,
for example, plating with a gold-nickel alloy with a mass fraction of gold 93.0-95.0%, nickel 5.0-7.0%
designate Zl-H (93.0-95.0).
In the designation of the coating with alloys based on precious metals of watch parts and jewelry, it is allowed to indicate the average mass fraction of the components.
For newly developed alloys, the components are designated in the order of decreasing their mass fraction.

12. Designation of coatings with alloys

Name material alloy coating	Designation	Name material alloy coating	Designation
Aluminum-zinc		Gold-copper-cadmium
Gold Silver		Cobalt gold
Gold-Silver-Copper		Gold-Nickel-Cobal
Gold-antimony		Gold-platinum
Gold-nickel		Indium gold
Gold-zinc-nickel		Copper-tin (bronze)
Gold-copper		Copper-tin-zinc (brass)
Copper-zinc (brass)	M-C	Tin Lead	O-S
Copper-lead-tin (bronze)	M-C-O	Tin zinc	O-C
Nickel-boron	N-B	Palladium-Nickel	Pd-N
Nickel-tungsten	H-B	Silver-copper	Wed-M
Nickel-iron	H-F	Silver-antimony	Wed-Su
Nickel-cadmium	N-Kd	Silver-palladium	Wed-Pd
Nickel-cobalt	N-Co	Cobalt-tungsten	Ko-B
Nickel-phosphorus	N-F	Cobalt-tungsten-vanadium	Ko-W-Wah
Nickel-Cobalt-Tungsten	N-Co-B	Cobalt-manganese	Ko-Mts
Nickel Cobalt Phosphorus	N-Co-F	Zinc-nickel	C-N
Nickel-chromium-iron	H-H-J	Zinc titanium	Ts-Ti
Tin-bismuth	O-wee	Cadmium titanium	Cd-tee
Tin-cadmium	O-cd	Chromium vanadium	X-Wah
Tin-cobalt	Eye	Chromium-carbon	X-Y
Tin Nickel	HE	Titanium nitride	Ti-Az

In the designation of the coating material obtained by the firing method, indicate the brand source material(pastes) in accordance with the normative and technical documentation. In the designation of the hot solder coating, the grade of the solder is indicated according to GOST 21930-76, GOST 21931-76.
The designations for non-metallic inorganic coatings are given below:

If it is necessary to indicate the electrolyte (solution) from which the coating is required, use the designations given in the mandatory annexes to GOST 9.306-85.
Electrolytes (solutions) not specified in the annexes are designated by their full name,
For example,

C9. ammonium chloride. xp, M15. pyrophosphate.

13. Designation of the functional properties of coatings.

14. Symbols decorative properties coatings

* The color of the coating, which corresponds to the natural color of the deposited metal (zinc, copper, chromium, gold, etc.), does not serve as a basis for classifying the coating as colored. The color of the coating is indicated by the full name, with the exception of the black coating -p.

15. Notation additional processing coverings

Additional coating treatment	Designation
Hydrophobization
Filling in water
Filling in chromate solution
Application paintwork
Oxidation
Reflow
Impregnation (varnish, glue, emulsion, etc.)
Oil impregnation
Heat treatment
Toning
Phosphating
Chemical staining, including filling in dye solution	Color name
Chromating *
Electrochemical staining	e-mail Color name

* If necessary, indicate the color of the chromate film:
khaki - khaki, colorless - btsv; rainbow film color - no designation.
The designation of additional treatment of the coating by impregnation, hydrophobization, application of paint and varnish coating may be replaced by the designation of the grade of the material used for additional processing.
The grade of the material used for additional treatment of the coating is designated in accordance with the regulatory and technical documentation for the material.
The designation of a specific paint and varnish coating used as an additional treatment is made in accordance with GOST 9.032-74.
Production methods, coating material, designation of the electrolyte (solution), properties and color of the coating, additional processing that are not listed in the standard are designated according to the technical documentation or recorded by the full name.
The order of designation of the coating in the technical documentation:
designation of the method of processing the base metal (if necessary);
designation of the method of obtaining the coating;
designation of the coating material;
minimum coating thickness;
the designation of the electrolyte (solution) from which it is required to obtain a coating (if necessary) (Table 15 a; 15 b);
designation of the functional or decorative properties of the coating (if necessary);
designation of additional processing (if necessary).

In the designation of the coating, the presence of all of the listed components is not necessary.
If necessary, in the designation of the coating, it is allowed to indicate the minimum and maximum thickness with a hyphen.
It is allowed to indicate the method of production, material and thickness of the coating in the designation of the coating, while the remaining components of the symbol are indicated in the technical requirements of the drawing.
The thickness of the coating, equal to or less than 1 micron, is not indicated in the designation, unless there is a technical need (with the exception of precious metals).

Coatings used as technological
(for example, zinc for zincate processing of aluminum and its alloys, nickel on corrosion-resistant steel, copper on copper alloys, copper on steel from cyanide electrolyte before acidic copper plating) may not be indicated in the designation.
If the coating is subjected to several types of additional processing, they are indicated in the technological sequence.
The coverage designation is recorded in a line. All components of the designation are separated from each other by dots, with the exception of the coating material and thickness, as well as the designation of additional paintwork, which is separated from the designation of a metallic or non-metallic inorganic coating by a fraction.
The designation of the production method and coating material should be written with uppercase letter, the rest of the components - from lowercase.
Examples of recording the designation of coatings are given in table. sixteen.

15a. Designations of electrolytes for obtaining coatings (according to GOST 9.306-85)

Base metal	Coating name	Main components	Designation
Aluminum and its alloys		Chromic anhydride
		Oxalic acid, titanium salts
		Boric acid, chromic anhydride
Magnesium and its alloys		Ammonium bifluoride or potassium fluoride
		Ammonium bifluoride, potassium dichromate or chromic anhydride	fluorine. chromium
		Ammonium bifluoride, sodium dichromate, orthophosphoric acid	fluorine. chromium. phos

15b. Designation of coating solutions

Basic metal	Name coverings	Main components	Designation
Magnesium and its alloys		Potassium dichromate (sodium) with various activators Potassium dichromate (sodium) with various activators, hydrofluoric acid and potassium fluoride (sodium)	chromium. fluorine
Magnesium and its alloys		Caustic soda, potassium stannate, sodium acetate, sodium pyrophosphate
Steel, cast iron		Ammonium molybdate
	Phosphate	Barium nitrate, zinc monophosphate, zinc nitrate
	Phosphate	Barium nitrate, orthophosphoric acid, manganese dioxide
Magnesium and its alloys	Phosphate	Barium monophosphate, phosphoric acid, sodium fluoride

16. Examples of recording the designations of coatings

Coating	Designation
Zinc 6 microns thick with colorless chromating	Ц6.хр. btsv
Zinc, 15 microns thick with khaki chromating	Ts15. xr.haki
Zinc 9 microns thick with rainbow chromating followed by painting	C9. xr / lkp
Zinc, 6 microns thick, oxidized black
Zinc 6 microns thick, phosphated in a solution containing barium nitrate, zinc monophosphate, zinc nitrate, impregnated with oil	Ts6. phos. Ox. prm
Zinc, 15 microns thick, phosphated, hydrophobized	Ts15. phos. hfj
Zinc with a thickness of 6 microns, obtained from an electrolyte in which there are no cyanide salts	Ts6. non-cyanide
Cadmium 3 microns thick, with a nickel sublayer 9 microns thick, with subsequent heat treatment, chromated	H9. Kd3. t. xp
Nickel 12 microns thick, shiny, obtained on a vibron-rolled surface with subsequent polishing	vbr. H12. b
Nickel, 15 microns thick, shiny, obtained from electrolyte with brightening agent
Chrome with a thickness of 0.5-1 microns, shiny, with a sublayer of forces - nickel with a thickness of 9 microns	Nsil9. H. b
Chrome with a thickness of 0.5-1 microns, with a sublayer of semi-shiny nickel with a thickness of 12 microns, obtained on a satin-finished surface	stn. Npb12. X
Chrome 0.5-1 microns thick, shiny with a copper sublayer 24 microns thick and two-layer nickel 15 microns thick	M24. Nd. 15. H. b
Chrome 0.5-1 microns thick, shiny, with a copper sublayer 30 microns thick and three-layer nickel 15 microns thick	M30. NT15. H. b
Chrome with a thickness of 0.5-1 microns, shiny with a sublayer of a two-layer nickel composite coating with a thickness of 18 microns
Chrome two-layer 36 microns thick: "milky" 24 microns thick, solid 12 microns thick	Xd36; Khmol24; X12. tv
Coating with a tin-lead alloy with a mass fraction of tin 55-60% thick 3 microns, melted	0-C (60) Z.opl.
Coating with a tin-lead alloy with a mass fraction of tin of 35-40% and a thickness of 6 microns, with a nickel sublayer with a thickness of 6 microns
Tin, 3 microns thick, crystalline, followed by painting
Copper 6 microns thick, shiny, tinted a blue color, followed by painting	MB. b. tn. blue / lkp
Plating with a gold-nickel alloy 3 microns thick, with a nickel sublayer 3 microns thick	NZ.Zl-N (98.5-99.5) 3
Gold, 1 μm thick, obtained on the surface after diamond cutting
Chemical nickel, 9 microns thick, hydrophobized	Chem. H9. gfzh; Chem. H9. gfzh 139-41
Chemical phosphate oil impregnated	Chem. Phos. prm
Chemical phosphate obtained in a solution containing barium nitrate, zinc monophosphate, zinc nitrate	Chem. Phos. oks
Chemical oxide conductive	Chem. Oaks. eh
Chemical oxide obtained in a solution containing sodium hydroxide, potassium stannate, sodium acetate, sodium pyrophosphate, followed by painting	Chem. Oaks. mill / lkp
Chemical oxide obtained in a solution of potassium (sodium) dichromate with various activators	Chem. Oaks. chromium
Chemical oxide obtained in a solution containing ammonium molybdate, impregnated with oil	Chem. Oaks. mdn. prm
Anodic-oxide solid, filled in a solution of chromates	AN. Oaks. tv nhr
Anodic-oxide electrical insulating with subsequent application of paint and varnish coating	AN. Oaks. eiz / lkp
Anodic oxide solid impregnated with oil	AN. Oke. tv prm; AN. Oaks. tv oil 137-02
Anodic oxide obtained on a hatched surface	pcs. AN. Oaks
Anodic oxide, obtained colored green in the process of anodic oxidation	Anotsvet. green
Anodic oxide, electro colored chemically in dark gray	AN. Oaks. Email dark grey
Anodic oxide obtained on a chemically polished surface, chemically painted red	xn. AN. Oaks. Red
Anodic oxide obtained in an electrolyte containing chromic anhydride	AN. Oaks. chromium
Anodic oxide, obtained in an electrolyte containing oxalic acid and titanium salts, solid	AN. Oaks. emt. tv
Anodic oxide obtained on a matted surface in an electrolyte containing boric acid, chromic anhydride	mt. AN. Oaks. umt
Hot coating obtained from POS 61 solder	Mountains. POS61
Silver, 9 microns thick, with a 3 micron chemical nickel sublayer	Chem. H3. Wed9
Coating obtained by chemical passivation, hydrophobized	Chem. Pas.hfzh

State standard of the union of the USSR

one system protection against corrosion and aging

COATINGS METAL AND
NON-METALLIC INORGANIC

Are common requirements

Unified system of corrosion and aging protection.
Metal and non-metal inorganic coatings.
General requirements

GOST
9.301-86

( STCMEA 5293-85,
STCMEA 5294-85
STCMEA 5295-85,
STCMEA 6442-88
STCMEA 6443-88,
STCMEA 4662-84
STCMEA 4664-84,
STCMEA 4665-84
STCMEA 4816-84)

Date of introduction 01.07.87

Content

This standard applies to metallic and non-metallic inorganic coatings (hereinafter referred to as coatings) obtained by electrochemical, chemical and hot (tin and its alloys) methods, and establishes General requirements(hereinafter referred to as requirements) to the surface of the base metal and coatings in the process of their production and quality control of the base metal and coatings.

The standard does not apply to coatings used as technological subcoats, to nickel, nickel-chrome, copper-nickel and copper-nickel-chrome, which have only a decorative purpose, and does not take into account changes in coatings that appeared during assembly and testing of the product.

Requirements not provided for in this standard, related to the specifics of parts, production and requirements for coatings, are indicated in the normative technical and (or) design documentation.

Compliance of coatings with the requirements of this standard is controlled by methods according to GOST 9.302-79.

(Modified edition, Amendment No. 2).

1. REQUIREMENTS FOR THE SURFACE OF THE BASE METAL

1.1. The roughness of the base metal surface in accordance with GOST 2789-73, microns, should be no more than:

R a 10 ( Rz 40) - for protective coatings;

R a 2.5 ( Rz 10) - for protective and decorative coatings;

R a 1.25 ( Rz 6,3) - for solid and electrical insulating anodic oxide coatings.

The roughness of the surface of the base metal for functional coatings must correspond to that established in the normative-technical and (or) design documentation for the product.

The specified requirements for surface roughness do not apply to non-working, hard-to-reach and non-working internal surfaces of parts, threaded surfaces, cut surfaces of stamped parts up to 4 mm thick, corrugated surfaces, as well as to parts whose base metal roughness is established by the relevant standards. The need to bring the surface roughness to the specified values should be specified in the design documentation.

1.2. Sharp corners and the edges of parts, with the exception of technically justified cases, must be rounded off with a radius of at least 0.3 mm; the radius of curvature of parts for solid and electrical insulating anodic-oxide coatings is not less than 0.5 mm.

1.3. On the surface of parts it is not allowed:

rolled scale, burrs;

delamination and cracks, including those revealed after etching, polishing, grinding;

corrosion damage, pores and cavities.

(Modified edition, Amendment No. 1).

1.4. The surface of cast and forged parts must be free of gas and shrinkage cavities, slag and flux inclusions, adhesions, underfilling, cracks.

The permissible deviations on the surface of cast parts (type, size and quantity) are established in the normative, technical and design documentation.

1.5. The surface of parts made of hot-rolled metal must be free of scale, pickling sludge, corrosion products of the base metal and other contaminants.

1.6. The surface of parts after machining must be free of a visible layer of grease or emulsion, metal shavings, burrs, dust and corrosion products without the introduction of foreign material particles.

1.5, 1.6.

1.7. The surface of parts after abrasive treatment, for example, hydrosandblasting, tumbling, etc., must be free of pickling sludge, slag, corrosion products and burrs.

1.8. The surface of the ground and polished parts must be uniform, without nicks, dents, burns, scratches, burrs, defects from the straightening tool.

1.9. On the surface of parts after heat treatment (annealing, quenching, normalization, tempering, aging, as well as heat treatment, carried out to improve the adhesion of subsequent coatings) there should be no nicks, scratches, cracks, bubbles, corrosion foci, delamination, warpage.

1.10. Welded and soldered seams on parts must be cleaned, continuous along the entire perimeter to eliminate gaps and electrolyte penetration into them.

Defects that appear when cleaning the seams made with medium-melting solders must be eliminated by soldering with the same or low-melting solders.

On the surface of the solder joints, uniform spreading of solder up to 10 mm wide, separate blind pores, cleaned of flux residues and not violating the tightness of the soldered seams, are allowed.

Seams on parts made of titanium alloys should be made using methods that exclude oxidation.

Mechanical cleaning of seams on parts made by soldering in molten salts is not allowed. Solder seams on such parts must be smooth and tight. There should be no flux residues and silumin splashes on the surface of the parts.

The glue seams on the parts must be continuous, without swelling, bubbles and voids, not have gaps into which electrolyte can penetrate, not contain excess glue in the near-seam area and be cleaned mechanically.

It is not allowed to apply chemical and electrochemical coatings to parts with adhesive joints.

1.11. The surface of electropolished parts must be smooth, light and shiny without etching, burns, cracks, unwashed salts, and corrosion products.

The gloss level is not standardized.

On electropolished surfaces are not rejected following signs:

uneven gloss in areas with different heat and mechanical treatment;

separate matte and whitish areas on the surface of parts, which are not subject to decorative requirements;

no electropolishing effect in hard-to-reach places: cracks, gaps, blind holes up to 15 mm in diameter, through holes up to 10 mm in diameter, as well as holes and recesses that are difficult to access for electropolishing;

traces of water drips;

lack of shine in the places of welding;

traces of contact with the device in the form of matte and dark areas;

mechanical polishing (if necessary) of the places of contact with the device and to obtain the exact dimensions of the part after electropolishing;

black dots on the thread, if there are no other instructions in the normative and technical documentation;

traces of machining of the base metal before electropolishing and other deviations allowed by the normative and technical documentation for the base metal.

1.9-1.11. (Modified edition, Amendment No. 1).

2. REQUIREMENTS FOR COATINGS

2. 1. Requirements for the appearance of the coating

2.1.1. The surface of the polished coating should be uniform, shiny or mirror-like.

On the mechanically polished surface of the coating, except for the mirror one, single hair-like scratches or dots from polishing pastes and straightening tools in an amount of no more than 5 pieces are not rejection signs. per 100 cm 2, edge polishing, slight waviness (tightening) of the coating on brass parts, if there are no special requirements in the design documentation.

2.1.2. On the surface of coatings, if there are no special instructions in the design documentation, the following signs are not rejection ones:

traces of machining and other deviations allowed by the normative and technical documentation for the base metal;

slight waviness of the coating surface after drawing, which is revealed after etching;

dark or light stripes or spots in hard-to-clean holes and grooves, on internal surfaces and concave areas of parts of complex configuration, mating points of one-piece assembly units, in welded, soldered seams, near-weld zone and places where the cladding layer is removed;

uneven gloss and color unevenness;

non-uniformity of color of coatings on parts made of clad metals with partial machining;

traces of water drips, chromating and phosphating solutions without salt residues;

shiny dots and streaks resulting from contact with measuring tool, fixtures and from collision of parts during the coating process in drums, bells and mesh fixtures;

change in color intensity or darkening after heating in order to dehydrate and check adhesion strength, remove insulation and impregnation;

single black dots in areas intended for filling with compounds, sealants, adhesives;

lack of coverage:

in the pores, places of inclusions allowed by the normative and technical documentation for casting;

on welded and soldered seams and around them at a distance of no more than 2 mm on one and the other side of the seam and in inner corners mutually perpendicular planes, subject to the subsequent additional protection of these places;

in the places of contact of the part with the device, except for special cases stipulated in the design documentation.

2.1.3. When two coatings are deposited on the surface of a part side by side without insulation or with the use of insulation, as well as when local coatings are deposited, if this does not affect the performance of the product, the following signs are not rejection:

displacement of the boundaries of coatings up to 2 mm, and for coatings with gold, palladium, rhodium and their alloys up to 1 mm in one direction or the other;

individual point inclusions of one coating on the surface of another; point inclusions of the coating metal on the insulated surface;

darkening of the metal at the border of the coatings;

tarnishing on uncovered surfaces.

2.1.2, 2.1.3. (Modified edition, Amendment No. 1).

2.2. Requirements for coating thickness

2.2.1. Exceeding the maximum coating thickness is not a rejection sign if it does not affect the assembly and performance of the product.

(Revised edition, Rev. No. 1).

2.2.2. In holes, grooves, cutouts, on concave sections of complexly shaped parts, on internal surfaces and mating points of one-piece assembly units, the coating thickness can be reduced by up to 50%, and for chrome coatings - no, if there are no other requirements in the design documentation for the coating thickness in these areas ...

2.2.3. In blind smooth and threaded holes and grooves with a diameter (or width) of up to 12 mm and in through smooth and threaded holes and grooves with a diameter (or width) of up to 6 mm, the thickness of the coating at a depth of more than one diameter (or one width) is not standardized; the absence of a coating is allowed if the design documentation does not specify the requirements for the thickness of the coating in these areas.

2.3. The coating must be firmly adhered to the base metal.

2.4. In appearance, thickness and other indicators, the coating must meet the requirements of table. 1 -19.

(Modified edition, Amendments No. 1, 2).

2.5. The conditions of storage and transportation of parts must exclude mechanical and chemical influences leading to damage to the coating.

Table 1

Zinc and cadmium coatings. Chromate coatings on zinc and cadmium coatings. Phosphate coating on zinc coating

Indicator name	Coating requirements
Appearance	The color of the zinc coating is light gray or silvery gray with a bluish tint.
	Cadmium coating color light gray or silver gray
	The color of the zinc coating with colorless chromating is silver-gray or silver-gray with a bluish tint. Slight rainbow shades are allowed.
	The color of the zinc coating with iridescent chromating is greenish-yellow with iridescent shades.
	The color of the iridescent chromated cadmium coating is golden yellow with iridescent shades.
	Zinc chromated khaki color with various shades.
	Cadmium coating color with khaki chromate from khaki to brown.
	Black chromated zinc coating black or black with green tint... Gray and rainbow shades are allowed on the concave areas of parts of complex configuration.

	matte surface after surface preparation by hydro-sandblasting and metal-sandblasting, tumbling, etching;
	darkening or weakening of the color intensity of the chromate coating on the parts after heat treatment;
	a darker or lighter shade of chromate coating in holes and grooves, on internal surfaces and concave areas of parts of complex configuration, mating points of one-piece assembly units, sharp edges, corners, places of contact with the device, between coils of springs with a small pitch;
	matte stripes around the holes;
	single mechanical damage of chromate coating no more than 2%. total area.
	The color of the zinc coating is phosphated from light gray to dark gray. It is not a rejection sign insignificant white bloom in blind holes, grooves, etc. The phosphate coating on the zinc coating must be uniform and dense.
	The following are not allowed on the surface:
	sludge deposition;
	uncoated streaks or spots; scratches reaching the base metal; hotbeds of corrosion; contamination from oils, greases or surfactants - for coatings intended for the application of paint and varnish coatings. "
Thickness for zinc and cadmium coatings
Coating mass per unit surface area	Colorless chromate coating - up to 0.5 g / m 2.
	Iridescent chromate coating - up to 1.0 g / m 2.
	Khaki colors chromate coating - over 1.5 g / m 2.
	Phosphate coating intended for impregnation - not less than 5.0 g / m 2.
	The coating intended for paintwork is in accordance with the requirements of GOST 9.402-80
Structure	Phosphate coating intended for paintwork must have a microcrystalline structure
Protective properties	When testing chromate coatings with a solution of lead acetic acid, a continuous dark spot should not appear before the specified time has elapsed. When testing the phosphate coating, the color of the test solution droplet shall not change to black within the specified time.
Completeness of flushing	The specific electrical conductivity of water after washing the phosphate coating intended for paintwork should not exceed three times its initial value
Oil absorption	Oil absorption of the phosphate coating - not less than 2.0 g / m 2

table 2

Copper plating and copper alloy plating

Indicator name	Coating requirements
Appearance	The color of the copper coating ranges from light pink to dark red. The shade is not standardized.
	The color of the high-tin copper-tin alloy is light gray to gray. The shade is not standardized.
	The color of the low-tin copper-tin alloy is light yellow. The shade is not standardized.
	Copper-zinc alloy coating color from light yellow to light pink.
	On the coating, there are no signs of discoloration, build-up of copper on the coating obtained for the purpose of protection against carburizing, darkening of the coating during storage before assembly
Thickness	In accordance with the requirements of the design documentation
Chemical composition	Mass fraction of copper in alloy coatings:
	M-O (60) - from 50 to 60%;
	M-O (88) - from 70 to 88%;
	M-C (90) - from 70 to 90%;
	M-C (70) - from 55 to 70%
Porosity	Coatings intended to protect against carburizing must be free of pores
Functional properties

Table 3

Nickel plated

Indicator name	Coating requirements
Appearance	The color of the matt nickel plating is light gray with a yellow tint, the shiny nickel plating is light gray. A darker color is allowed in the holes and grooves on the inner surfaces, concave areas of parts of complex configuration and at the interface of assembly units.
	The color of the electroless nickel plating is gray with a yellow tint.
	Darkening and iridescent shades after heat treatment, matte spots due to uneven etching of the base metal are not rejection signs. The color of the black and thermally oxidized coating is from black-gray to black. Tarnishing colors are allowed
Thickness	In accordance with the requirements of the design documentation.
	The thickness of the black nickel plating is not standardized.
	The thickness of the lower layer of a three-layer nickel coating Нд (Нпб.Нб) in relation to the total thickness of the coating is 50-70%; the thickness of the top layer is 50-30%.
	The thickness of the lower layer of the nickel three-layer coating Нт (Нпб.НсНб) in relation to the total thickness of the coating is 50% or more; middle layer - up to 10%, top - up to 40%.
Chemical composition	Mass fraction of sulfur in the lower layer of a nickel two-layer coating Нд (Нпб.Нб) up to 0.005%; in the top 0.05-0.09%.
	Mass fraction of sulfur in the lower layer of a three-layer nickel coating Нт (Нпб.НсНб) up to 0.005%; on average - not less than 0.15%; in the upper - 0.05-0.09%.
	Mass fraction of phosphorus in chemical nickel coating 3-12%
Porosity*	Not more than three through pores per 1 cm 2 of surface area and 1 cm of edge length. If the thickness of the coating is less than 24 microns or the thickness of nickel with a sublayer less than 12 microns is not standardized
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product
Protective properties	Also

Table 4

Chrome plated

Indicator name	Coating requirements
Appearance	The color of the glossy coating is light gray with a bluish tint.
	The color of the matte finish is light gray.
	The color of the hard (wear-resistant) coating is light gray with a bluish or milky-matte tint.
	The color of the two-layer (corrosion-resistant) coating is light gray.
	The color of microporous and microcracked coatings is from light gray to gray with a blue tint. The color of the microporous high-gloss coating obtained from trivalent chromium electrolytes ranges from light gray to dark gray.
	The color of the milky coating is light gray.
	Single point depressions up to 2% of the total area with a chromium thickness of more than 40 microns and a network of cracks with a chromium thickness of more than 24 microns are not rejection signs. The color of the black coating is black with a blue or brown tint.
	A gray tint in the inner corners, recesses and holes of complexly shaped parts is not a rejection feature.
Thickness	In accordance with the requirements of the design documentation
Porosity	No more than three through pores per 1 cm 2 of surface area and 1 cm of edge length, unless otherwise indicated in the design documentation *.
	The porosity of milk chrome less than 24 microns thick, protective and decorative two-layer less than 21 microns thick and wear-resistant less than 40 microns thick is not standardized *.
	The number of pores on the surface of the microporous coating (X mp) when evaluated using optical microscopes with a magnification of at least 100 × should be at least 10,000 per cm 2.
	The porosity of black chromium is not standardized.
	On the surface of the chrome microcrack coating (X mt) there must be at least 250 cracks at a length of 1 cm in all directions, forming a network of cracks
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product
Functional properties	Coating hardness - according to GOST 9.303-84
Protective properties	Also
	When testing the phosphate coating, the color of the test solution droplet shall not change to black within the specified time.

* Requirements apply to the coating on steel parts.

(Amendment. IUS 1-1991)

Table 5

Tin plating and tin alloy plating

Indicator name	Coating requirements
Appearance	The color of fused and unmelted coatings ranges from light gray to gray. The melted coating is shiny. Uneven gloss on one part is allowed.
	The color of the coating with a tin-nickel alloy is light gray. Pink and purple shades are allowed.
	The color of the coating with a tin-lead alloy is from light gray to dark gray. The shade is not standardized.
	The color of the tin-bismuth coating is from light gray to gray.
	Metal beads that do not interfere with assembly and do not affect the functional properties of the coating are not a rejection sign.
Thickness
Chemical composition	Tin coatings intended for use in contact with food should contain no more than 0.1% lead and no more than 0.025% arsenic
	Mass fraction of tin in alloy coatings:
	O-H (65) - from 50 to 70%;
	O-S (60) - t 50 to 70%;
	O-C (40) -30 to 50%;
	O-C (12) - from 8 to 15%.
	Mass fraction of bismuth in the O-Vi (99.8) alloy coating from 0.2 to 4.0%
Porosity*	Not more than three through pores per 1 cm 2 of surface area and 1 cm of edge length, unless otherwise indicated in the design documentation.
Porosity*	With a coating thickness of 6 microns or less, it is not standardized
Functional properties
Protective properties	Also

* Requirements apply to the coating on steel parts.

Table 6

Hot tin and tin-lead alloy coatings

Indicator name	Coating requirements
Appearance	Tin plating color is from light gray to gray, tin-lead alloy plating color is from gray to dark gray. The coating is glossy or matte, smooth. The gloss level is not standardized.

	slight sagging and unevenness of the coating thickness, which do not interfere with the soldering or work of the part;
	spatter and metal drops that are firmly adhered to the base, do not interfere with the work of the part, on non-working and working (according to the sample) surfaces, as well as on surfaces on which coating is not provided, except for sliding surfaces;
	dark spots on the coating on the inner surfaces of blind holes;
	slight tuberosity along the entire length of the wire and a depression from the contact of the wire with the guide roller, not reaching the base metal;
	non-uniformity of the color of the coating.
	Not allowed:
	rough nodules;
	dark spots, dots, non-rubbing film of white or Brown;
	cracks, coating delamination, uncovered areas;
	solder splashes on work surfaces coated with precious metals (gold, silver, palladium, etc.);
	acid flux residues
Thickness	Not standardized
Chemical composition	The chemical composition of coatings with tin-lead alloys must correspond to the chemical composition of the main components of solders in accordance with GOST 21930-76 and GOST 21931-76
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 7

Silver plated and silver-antimony alloy plated

Indicator name	Coating requirements
Appearance	The color of the silver plating and the silver-antimony alloy plating is silvery-white.
	The color of the silver coating made from electrolytes with brightening additives and the silver chromated coating is white with a yellowish tinge.
	The color of the chemical silver plating is white.
	The color of the blackened silver coating is from a dark gray child.
	The following signs are not considered defective:
	dark spots, stripes and discoloration in blind holes, grooves, in concave areas of parts of complex configuration;
	darkening of the coating during storage before assembly and color change from light pink to light brown after heat treatment, pressing into plastic, provided that functional properties are retained
Thickness	In accordance with the requirements of the design documentation
Chemical composition	Mass fraction of antimony in the coating with Sr-Su alloy from 0.4 to 2%
Porosity
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 8

Gold plating and gold alloy plating

Indicator name	Coating requirements
Appearance	Gold plating color from light yellow to dark yellow
	The color of the coating with gold-nickel alloy is from light yellow to yellow.
	Coating color with gold-cobalt alloy from orange-yellow to yellow
Thickness	In accordance with the requirements of the design documentation
Chemical composition	Mass fraction of nickel in the coating with Zl-N alloy and mass fraction of cobalt in the coating with Zl-Ko alloy - in accordance with the requirements of GOST 9.303-84
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 9

Palladium plated

Indicator name	Coating requirements
Appearance	Coating color from light gray to gray with a yellow tint.
Appearance	Single dark spots, iridescent shades from light brown to violet, formed during heating, provided that the functional properties are preserved
Thickness	In accordance with the requirements of the design documentation
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 10

Rhodium plated

Indicator name	Coating requirements
Appearance	Coating color light gray with a blue tint
Thickness	In accordance with the requirements of the design documentation
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product.

Table 11

Chemical oxide coating on steel and cast iron

Indicator name	Coating requirements
Appearance	Coating color Chem. Ox (including after oil impregnation) on parts made of carbon and low-alloy steels, black with a blue tint. On parts obtained by casting, a black coating with a gray or brown shade is allowed.
	The color of the coating on high-alloy steel parts is from dark gray to dark brown with a cherry tint.
	The color of the coating on parts made of cast iron and silicon alloyed steels is from light yellow to dark brown.
	The color of the coating on high carbon tool steel parts is black with gray tint
	Non-uniformity of color and shade is allowed on parts that have undergone local hardening, welding, carburizing, peening and other machining; red tint of coatings on small profiled parts and between coils of springs with a small pitch, light gray - on sharp edges of parts
Thickness	Not standardized
Protective properties	On the Khim.Oks coating after testing for a specified time, there should be no spots of contact released copper.
Protective properties	On the coating Chem.Ox. prm after the tests there should be no foci of corrosion, with the exception of sharp edges and ends of the springs, on which no more than three points of corrosion are allowed per 1 cm 2 of the surface area and per 1 cm of the edge length

Table 12

Chemical passivation coating
on corrosion-resistant steels.

Indicator name	Coating requirements
Appearance	Coating color Chem.Pas. must match the color of the metal being processed.
	The following signs are not considered defective:
	iridescent shades, depending on the steel grade, including in the places of welding, bending;
	slight darkening;
	traces of mechanical finishing;
	black inclusions in the form of separate small dots
Thickness

Table 13

Chemical oxide and anodic-oxide coatings on copper and its alloys

Indicator name	Coating requirements
Appearance	Coating color Chem.Ox and An.Ox from dark red with a brown tint to black with a blue tint

	traces of mechanical finishing of the base metal surface;
	partial lack of coverage on sharp edges;
	darkening between coils of springs with a small pitch.
	The color of the Chem.Pas coating must correspond to the color of the processed metal.
	The following signs are not considered defective:
	rainbow shades;
	darkening of the coating between the coils of the springs with a small pitch;
	non-uniformity of the varnish film in color and varnish drips after varnishing, which do not interfere with assembly and do not affect the performance of the product
Thickness	Not standardized
Protective properties	When tested on a Chem.Pas coating, there should be no change in the color of the drop to blue before the specified time has elapsed.

Table 14

Chemical oxide coating on aluminum and its alloys

Indicator name	Coating requirements
Appearance	Coating color Chem.Ox from gray-blue to dark blue or from light blue to green or yellow
	on alloys of grades D16, D1, D24F - greenish-blue with or without rainbow shades;
	on cast alloys - blue-gray with black and brown stains.
	The color of the coating Chem.Pas corresponds to the color of the base metal.
	Coating color Chem.Ox.e from colorless to light blue or light yellow; golden yellow to brown with iridescent shades on wrought alloys; gray with yellow and brown streaks on cast alloys.
	The following signs are not considered defective:
	dark and light stripes in the direction of rolling, soldering and welding points;
	darkening on parts soldered high temperature brazing;
	separate stains from chrome salts around the holes, in the places of contact of parts with the device, in the places of conjugation of one-piece assembly units, around the pores and places of inclusions allowed by the normative and technical documentation for casting;
	revealing the structure of the base metal
Thickness	Not standardized
Protective properties
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 15

Anodic oxide coating on aluminum and its alloys

Indicator name	Coating requirements
Appearance	The color of An.Ox coating is from light gray to dark gray, on parts made of cast alloys from light gray to dark brown. The shade is not standardized.
	The color of the painted coating must match the color of the sample. The shade is not standardized. On multicomponent and cast alloys, reflections of various tones are possible.
	Coating color An.Ox.chrom from milky to gray, rainbow shades are possible.
	Coating color An.Ox.nkhr from light green to yellow-green, on multicomponent and casting alloys from gray to dark gray. The shade is not standardized.
	The following signs are not considered defective:
	dark points and spots as a result of revealing the heterogeneity of the base metal structure;
	dark and light stripes in the direction of rolling, places of welding, lapping, work hardening, places where the cladding layer is absent;
	yellow spots from chromium salts around the holes, in the places of contact of the part with the device, in the places where one-piece assembly units are mated, around the pores and places of inclusions allowed by the normative and technical documentation for casting.
	The color of the coating An.Ox.tv is from light gray to black, yellow-green shades are allowed.
	Coating color An.Ox.es from light yellow to dark brown or from light gray to dark gray.
	The color of the coating An.Ox.tv and An.Ox.eiz after filling with chromates from yellow-green to brown-black.
	The presence of microcracks on the An.Ox.ex coating is not a rejection sign if they do not affect the functional properties.
	The color of the coating An.Ox.emt is from light gray to dark gray, depending on the alloy used, enamel-like. The shade is not standardized.
	The color of the painted coating must match the color of the sample
	Coating color Anotsvet light brown, gray-blue, blue-black, golden, golden-bronze, bronze, gray-brown.
	A lighter tone is allowed on the inner surfaces of parts
Thickness	In accordance with the requirements of the design documentation
Coating filling quality	After testing, the weight loss of the sample should not exceed 20 mg / dm 2 for products intended for operation in an open atmosphere, and 30 mg / dm 2 for products intended for use in an enclosed space.
Coating filling quality	After the tests, the coating should not be stained or may be slightly stained!
Completeness of flushing	The specific electrical conductivity of water after washing the coating An.Ox.eiz should not exceed three times its initial value
Protective properties	When tested, there shall be no change in the color of a drop of the test solution before the specified time has elapsed.
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 16

Anodic oxide coating on titanium alloys

Indicator name	Coating requirements
Appearance	Coating color Anotsvet from blue to blue, pink, green, yellow. The shade is not standardized.
	Traces of mechanical finishing of the surface of the base metal are not a rejection sign.
	Coating color An.Ox from light gray to dark gray
Thickness	Not standardized
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 17

Chemical oxide and anodic oxide coatings
on magnesium and magnesium alloys

Indicator name	Coating requirements
Appearance	Coating color Khim.Oks from straw yellow to dark brown or black.
	Coating color Chem.Phos from light gray to dark gray.
	Coating color Anosvet is yellow, green or gray-black. The shade is not standardized.
	The following signs are not considered defective:
	tarnish colors; stains resulting from re-oxidation; point areas of metal without coating around the pores; gray spots with smearing deposits on the ML-5 alloy;
	black spots on machined surfaces resulting from local heating of the metal during machining
Thickness	Coating thickness Chem.Ox is not standardized, An.Ox - in accordance with the requirements of design documentation

Table 18

Phosphate coating on steel and cast iron

Nameindicator	Coverage requirements
Appearance	Coating color from light gray to black, after impregnation with oil, emulsion or after hydrophobization from dark gray to black.
	The following signs are not considered defective:
	heterogeneity of crystal sizes in areas of local hardening, welding, work hardening, various surface roughness in decarburized areas;
	white bloom, removed by wiping;
	deposits of phosphate sludge on non-working surfaces;
	traces of a copper electrode on parts welded with spot or roller welding;
	stains, streaks and streaks after wiping with an emulsion, varnish or after hydrophobization, which do not interfere with assembly and do not affect the performance of the product;
	yellow spots from chrome salts around holes, places of contact of a part with a device and places of conjugation of assembly units, spots around pores and places of inclusion allowed by regulatory and technical documentation for casting
Coating mass per unit surface area	Coating mass per unit of surface area before impregnation - not less than 5 g / m 2; on a surface with roughnessR a 1.25-0.63 microns, it is allowed to reduce the coating mass per unit surface area in accordance with the requirements of the normative and technical documentation.
Coating mass per unit surface area	Coating mass per unit surface area before applying paint and varnish in accordance with the requirements of GOST 9.402-80
Structure	The coating intended for paintwork must have a microcrystalline structure.
Protective properties	When tested in accordance with GOST 9.302-88, the color of the drop should not change during the specified time or after the test, there should be no foci of corrosion on the coating, with the exception of sharp edges, mating points of one-piece assembly units, where no more than three pinpoint foci of corrosion per 1 cm 2 are allowed surface area and 1 cm of edge length
Oil absorption	Not less than 2.0 g / m 2
Completeness of flushing	The specific electrical conductivity of water after washing the coating intended for the paintwork should not exceed three times its initial value.

Table 19

Chemical oxide chromate and phosphate coatings on zinc alloys

Indicator name	Coating requirements
Appearance	Coating color Khim.Oks.chrom greenish-yellow with iridescent shades; in the presence of a copper alloy, the color of the coating is gray-blue; Coating color Chem.Phos from light gray to gray.
	The following signs are not considered defective:
	a matte surface and a weakening of the color intensity of the chromate coating on parts after heat treatment, hydro-sandblasting, tumbling and etching;
	a darker or lighter shade of chromate coating in holes and grooves, on internal surfaces and on concave areas of parts of complex configuration, at the interface of one-piece assembly units, on sharp edges, corners, at points of contact with the device, between coils of springs with a small pitch;
	matte stripes around the holes
	single mechanical damage of chromate coating not more than 2%
Thickness	Not standardized

3. REQUIREMENTS FOR QUALITY CONTROL OF BASE METAL AND COATINGS

3.1. Before applying coatings, 2-5% of parts from a batch, but not less than three parts, and for parts of a single production - each part is controlled for compliance with paragraphs. 1.1 -1.10.

3.2. Semi-finished products (tape, wire, etc.) are subject to incoming control for compliance with the requirements of regulatory and technical documentation for the supply and the requirements of paragraphs. 1.1-1.6.

If there are unsatisfactory results, a second check is carried out on a doubled number of parts.

Upon receipt of unsatisfactory results of repeated inspection on at least one part, the entire batch is rejected and returned to the manufacturer.

3.3. If it is impossible to control the quality of coatings on parts, for example, large and heavy parts of a single production, it is allowed to carry out control on witness samples or to guarantee the quality of the coating by the correct execution of the technological process, confirmed by an entry in the log of control of the technological process.

Testimonial samples must be made of the material of the parts, have the same surface roughness and coatings applied using the same technology as applied to the parts.

The shape and size of the witness samples are developed by the enterprise and agreed in accordance with the established procedure.

The same witness samples and parts can be used for different proof tests.

3.4. Parts on which the coating was tested by destructive methods, as well as parts, the coatings of which do not meet the requirements of this standard, are allowed to be presented for acceptance after re-coating.

3.5. The control of the appearance of the coatings is carried out on 100% of the parts.

It is allowed to apply statistical control methods forGOST 18242-72.

Inspection of the appearance of the coating on parts covered in bulk and in automatic lines is allowed to be carried out on a sample of 2% of parts from each batch.

3.6. Control of the thickness of the coating is carried out before its additional processing, with the exception of brushing, polishing, grinding, chromating and phosphating.

The thickness control of the nickel coating, including that obtained by a chemical method, is carried out before heat treatment.

3.4-3.6.(Modified edition, Amendment No. 1).

3.7. 3.8... (Deleted, Amendment No. 1).

3.9. To control the coating thickness, adhesion strength and other quality indicators, 0.1 to 1% of parts are selected from each batch, but not less than three parts.

In technically justified cases, for example, for products of small-scale production or products with coatings with precious and rare metals and their alloys, it is allowed to set a sample of less than 0.1%, but not less than three parts.

The control of the coating thickness by the metallographic method is allowed to be carried out on one part.

Control of coating thickness on parts processed in automatic lines may be carried out at least once a shift.

3.10. The adhesion strength of coatings subjected to heat treatment, melting, brushing, grinding and polishing is evaluated after these operations.

3.9, 3.10... (Modified edition, Amendment No. 1).

3.11. Control chemical composition Alloy coatings are carried out at least twice a week, as well as after adjusting the electrolyte.

The content of phosphorus in the chemical nickel coating and sulfur in the protective and decorative nickel coating is allowed not to be controlled, but to be guaranteed by the correct execution of the technological process.

3.12... (Deleted, Amendment No. 1).

3.13. Control protective properties coatings obtained by Chem. Pass, An. Oke and Chem. Ox on copper and its alloys, intended for operation in conditions 1 according toGOST 15150-69, as well as these coatings, additionally protected by a paint-and-lacquer coating, are not carried out.

Control of protective properties of coatings Chem. Oaks and Chem. Fos on steel and cast iron is allowed to be carried out before or after their additional processing.

3.14. The need to control the coating mass per unit surface area, oil absorption, rinsing completeness, porosity, coating filling quality, protective properties of chromate coatings on zinc and cadmium coatings, phosphate coatings on zinc coatings and structures is established in the technical and (or) design documentation.

3.13, 3.14.(Modified edition, Amendment No. 1).

3.15. If unsatisfactory results are obtained for one of the indicators during the selective inspection of coatings, a repeated inspection is carried out on a doubled number of parts in the sample.

If the results are unsatisfactory during repeated inspection of coatings on one part, the entire batch is rejected or, in case of discrepancy in appearance, it is subjected to continuous control.

The repeated control of the adhesion strength of the coatings is not carried out. If unsatisfactory results are obtained during sampling, the entire batch is rejected.

(Introduced additionally, Amendment No. 1).

INFORMATION DATA

1. PERFORMERS

I.L. Moteeunas , Cand. chem. sciences; V.V. Protusyavichiene; D.G. Kovalenko; G.V. Kozlova , Cand. tech. sciences (topic leaders); N.G. Alberg; T.I. Berezhnyak; G.S. Fomin , Cand. chem. sciences; E.B. Davidavicius , Cand. chem. sciences ; S.Z. Navitskene; B.A. Arlauskienė

2. APPROVED AND INTRODUCED BY Decree State Committee USSR according to standards dated 02.27.86 No. 424

3. Inspection frequency 5 years

4. The standard corresponds to ST SEV 4662-84, ST SEV 4664-84, ST SEV 4665-84, ST SEV 4816-84, ST SEV 5293-85, ST SEV 5294-85, ST SEV 5295-85, ST SEV 6442- 88, ST SEV 6443-88 in terms of technical requirements

The standard complies with ISO 1456-88, ISO 1458-88, ISO 2081-86, ISO 2082-86, ISO 2093-86, ISO 6158-84, ISO 7599-83

5. Instead of GOST 9.301-78

6. REFERENCE REGULATORY TECHNICAL DOCUMENTS

7. REPUBLICATION with Amendments No. 1, 2, approved in March 1989, October 1989 (IUS 6-89, 1-90)

State standard of the union of the USSR

Unified system of protection against corrosion and aging

COATINGS METAL AND
NON-METALLIC INORGANIC

Are common requirements

Unified system of corrosion and aging protection.
Metal and non-metal inorganic coatings.
General requirements

GOST
9.301-86

( STCMEA 5293-85,
STCMEA 5294-85
STCMEA 5295-85,
STCMEA 6442-88
STCMEA 6443-88,
STCMEA 4662-84
STCMEA 4664-84,
STCMEA 4665-84
STCMEA 4816-84)

Date of introduction 01.07.87

Content

This standard applies to metallic and non-metallic inorganic coatings (hereinafter referred to as coatings) obtained by electrochemical, chemical and hot (tin and its alloys) methods, and establishes general requirements (hereinafter referred to as requirements) for the surface of the base metal and coatings during their production and quality control. base metal and coatings.

Requirements not provided for in this standard, related to the specifics of parts, production and requirements for coatings, are indicated in the normative technical and (or) design documentation.

Compliance of coatings with the requirements of this standard is controlled by methods according to GOST 9.302-79.

(Modified edition, Amendment No. 2).

1. REQUIREMENTS FOR THE SURFACE OF THE BASE METAL

1.1. The roughness of the base metal surface in accordance with GOST 2789-73, microns, should be no more than:

R a 10 ( Rz 40) - for protective coatings;

R a 2.5 ( Rz 10) - for protective and decorative coatings;

R a 1.25 ( Rz 6,3) - for solid and electrical insulating anodic oxide coatings.

The roughness of the surface of the base metal for functional coatings must correspond to that established in the normative-technical and (or) design documentation for the product.

1.2. Sharp corners and edges of parts, except for technically justified cases, must be rounded off with a radius of at least 0.3 mm; the radius of curvature of parts for solid and electrical insulating anodic-oxide coatings is not less than 0.5 mm.

1.3. On the surface of parts it is not allowed:

rolled scale, burrs;

delamination and cracks, including those revealed after etching, polishing, grinding;

corrosion damage, pores and cavities.

(Modified edition, Amendment No. 1).

1.4. The surface of cast and forged parts must be free of gas and shrinkage cavities, slag and flux inclusions, adhesions, underfilling, cracks.

The permissible deviations on the surface of cast parts (type, size and quantity) are established in the normative, technical and design documentation.

1.5. The surface of parts made of hot-rolled metal must be free of scale, pickling sludge, corrosion products of the base metal and other contaminants.

1.5, 1.6.

1.7. The surface of parts after abrasive treatment, for example, hydrosandblasting, tumbling, etc., must be free of pickling sludge, slag, corrosion products and burrs.

1.8. The surface of the ground and polished parts must be uniform, without nicks, dents, burns, scratches, burrs, defects from the straightening tool.

1.10. Welded and soldered seams on parts must be cleaned, continuous along the entire perimeter to eliminate gaps and electrolyte penetration into them.

Defects that appear when cleaning the seams made with medium-melting solders must be eliminated by soldering with the same or low-melting solders.

On the surface of the solder joints, uniform spreading of solder up to 10 mm wide, separate blind pores, cleaned of flux residues and not violating the tightness of the soldered seams, are allowed.

Seams on parts made of titanium alloys should be made using methods that exclude oxidation.

The glue seams on the parts should be continuous, without swelling, bubbles and voids, not have gaps into which electrolyte can penetrate, not contain excess glue in the near-seam zone and mechanically cleaned.

It is not allowed to apply chemical and electrochemical coatings to parts with adhesive joints.

1.11. The surface of electropolished parts must be smooth, light and shiny without etching, burns, cracks, unwashed salts, and corrosion products.

The gloss level is not standardized.

On an electropolished surface, the following signs are not considered to be defective:

uneven gloss in areas with different heat and mechanical treatment;

separate matte and whitish areas on the surface of parts, which are not subject to decorative requirements;

traces of water drips;

lack of shine in the places of welding;

traces of contact with the device in the form of matte and dark areas;

mechanical polishing (if necessary) of the places of contact with the device and to obtain the exact dimensions of the part after electropolishing;

black dots on the thread, if there are no other instructions in the normative and technical documentation;

traces of machining of the base metal before electropolishing and other deviations allowed by the normative and technical documentation for the base metal.

1.9-1.11. (Modified edition, Amendment No. 1).

2. REQUIREMENTS FOR COATINGS

2. 1. Requirements for the appearance of the coating

2.1.1. The surface of the polished coating should be uniform, shiny or mirror-like.

2.1.2. On the surface of coatings, if there are no special instructions in the design documentation, the following signs are not rejection ones:

traces of machining and other deviations allowed by the normative and technical documentation for the base metal;

slight waviness of the coating surface after drawing, which is revealed after etching;

uneven gloss and color unevenness;

non-uniformity of color of coatings on parts made of clad metals with partial machining;

traces of water drips, chromating and phosphating solutions without salt residues;

shiny dots and streaks formed from contact with a measuring tool, fixtures and from collision of parts during the coating process in drums, bells and mesh fixtures;

change in color intensity or darkening after heating in order to dehydrate and check adhesion strength, remove insulation and impregnation;

single black dots in areas intended for filling with compounds, sealants, adhesives;

lack of coverage:

in the pores, places of inclusions allowed by the normative and technical documentation for casting;

on welded and soldered seams and around them at a distance of no more than 2 mm on one and the other side of the seam and in the inner corners of mutually perpendicular planes, subject to the subsequent additional protection of these places;

in the places of contact of the part with the device, except for special cases stipulated in the design documentation.

displacement of the boundaries of coatings up to 2 mm, and for coatings with gold, palladium, rhodium and their alloys up to 1 mm in one direction or the other;

individual point inclusions of one coating on the surface of another; point inclusions of the coating metal on the insulated surface;

darkening of the metal at the border of the coatings;

tarnishing on uncovered surfaces.

2.1.2, 2.1.3. (Modified edition, Amendment No. 1).

2.2. Requirements for coating thickness

2.2.1. Exceeding the maximum coating thickness is not a rejection sign if it does not affect the assembly and performance of the product.

(Revised edition, Rev. No. 1).

2.3. The coating must be firmly adhered to the base metal.

2.4. In appearance, thickness and other indicators, the coating must meet the requirements of table. 1 -19.

(Modified edition, Amendments No. 1, 2).

2.5. The conditions of storage and transportation of parts must exclude mechanical and chemical influences leading to damage to the coating.

Table 1

Zinc and cadmium coatings. Chromate coatings on zinc and cadmium coatings. Phosphate coating on zinc coating

Indicator name	Coating requirements
Appearance	The color of the zinc coating is light gray or silvery gray with a bluish tint.
	Cadmium coating color light gray or silver gray
	The color of the zinc coating with colorless chromating is silver-gray or silver-gray with a bluish tint. Slight rainbow shades are allowed.
	The color of the zinc coating with iridescent chromating is greenish-yellow with iridescent shades.
	The color of the iridescent chromated cadmium coating is golden yellow with iridescent shades.
	Zinc chromated khaki color with various shades.
	Cadmium coating color with khaki chromate from khaki to brown.
	The color of the zinc coating with black chromating is black or black with a green tint. Gray and rainbow shades are allowed on the concave areas of parts of complex configuration.

	matte surface after surface preparation by hydro-sandblasting and metal-sandblasting, tumbling, etching;
	darkening or weakening of the color intensity of the chromate coating on the parts after heat treatment;
	a darker or lighter shade of chromate coating in holes and grooves, on internal surfaces and concave areas of parts of complex configuration, mating points of one-piece assembly units, sharp edges, corners, places of contact with the device, between coils of springs with a small pitch;
	matte stripes around the holes;
	single mechanical damage of chromate coating no more than 2%. total area.
	The color of the zinc coating is phosphated from light gray to dark gray. A slight white bloom in blind holes, grooves, etc. is not a sign of rejection. The phosphate coating on the zinc coating must be uniform and dense.
	The following are not allowed on the surface:
	sludge deposition;
	uncoated streaks or spots; scratches reaching the base metal; hotbeds of corrosion; contamination from oils, greases or surfactants - for coatings intended for the application of paint and varnish coatings. "
Thickness for zinc and cadmium coatings
Coating mass per unit surface area	Colorless chromate coating - up to 0.5 g / m 2.
	Iridescent chromate coating - up to 1.0 g / m 2.
	Khaki colors chromate coating - over 1.5 g / m 2.
	Phosphate coating intended for impregnation - not less than 5.0 g / m 2.
	The coating intended for paintwork is in accordance with the requirements of GOST 9.402-80
Structure	Phosphate coating intended for paintwork must have a microcrystalline structure
Protective properties	When testing chromate coatings with a solution of lead acetic acid, a continuous dark spot should not appear before the specified time has elapsed. When testing the phosphate coating, the color of the test solution droplet shall not change to black within the specified time.
Completeness of flushing	The specific electrical conductivity of water after washing the phosphate coating intended for paintwork should not exceed three times its initial value
Oil absorption	Oil absorption of the phosphate coating - not less than 2.0 g / m 2

table 2

Copper plating and copper alloy plating

Indicator name	Coating requirements
Appearance	The color of the copper coating ranges from light pink to dark red. The shade is not standardized.
	The color of the high-tin copper-tin alloy is light gray to gray. The shade is not standardized.
	The color of the low-tin copper-tin alloy is light yellow. The shade is not standardized.
	Copper-zinc alloy coating color from light yellow to light pink.
	On the coating, there are no signs of discoloration, build-up of copper on the coating obtained for the purpose of protection against carburizing, darkening of the coating during storage before assembly
Thickness	In accordance with the requirements of the design documentation
Chemical composition	Mass fraction of copper in alloy coatings:
	M-O (60) - from 50 to 60%;
	M-O (88) - from 70 to 88%;
	M-C (90) - from 70 to 90%;
	M-C (70) - from 55 to 70%
Porosity	Coatings intended to protect against carburizing must be free of pores
Functional properties

Table 3

Nickel plated

Indicator name	Coating requirements
Appearance	The color of the matt nickel plating is light gray with a yellow tint, the shiny nickel plating is light gray. A darker color is allowed in the holes and grooves on the inner surfaces, concave areas of parts of complex configuration and at the interface of assembly units.
	The color of the electroless nickel plating is gray with a yellow tint.
	Darkening and iridescent shades after heat treatment, matte spots due to uneven etching of the base metal are not rejection signs. The color of the black and thermally oxidized coating is from black-gray to black. Tarnishing colors are allowed
Thickness	In accordance with the requirements of the design documentation.
	The thickness of the black nickel plating is not standardized.
	The thickness of the lower layer of a three-layer nickel coating Нд (Нпб.Нб) in relation to the total thickness of the coating is 50-70%; the thickness of the top layer is 50-30%.
	The thickness of the lower layer of the nickel three-layer coating Нт (Нпб.НсНб) in relation to the total thickness of the coating is 50% or more; middle layer - up to 10%, top - up to 40%.
Chemical composition	Mass fraction of sulfur in the lower layer of a nickel two-layer coating Нд (Нпб.Нб) up to 0.005%; in the top 0.05-0.09%.
	Mass fraction of sulfur in the lower layer of a three-layer nickel coating Нт (Нпб.НсНб) up to 0.005%; on average - not less than 0.15%; in the upper - 0.05-0.09%.
	Mass fraction of phosphorus in chemical nickel coating 3-12%
Porosity*	Not more than three through pores per 1 cm 2 of surface area and 1 cm of edge length. If the thickness of the coating is less than 24 microns or the thickness of nickel with a sublayer less than 12 microns is not standardized
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product
Protective properties	Also

Table 4

Chrome plated

Indicator name	Coating requirements
Appearance	The color of the glossy coating is light gray with a bluish tint.
	The color of the matte finish is light gray.
	The color of the hard (wear-resistant) coating is light gray with a bluish or milky-matte tint.
	The color of the two-layer (corrosion-resistant) coating is light gray.
	The color of microporous and microcracked coatings is from light gray to gray with a blue tint. The color of the microporous high-gloss coating obtained from trivalent chromium electrolytes ranges from light gray to dark gray.
	The color of the milky coating is light gray.
	Single point depressions up to 2% of the total area with a chromium thickness of more than 40 microns and a network of cracks with a chromium thickness of more than 24 microns are not rejection signs. The color of the black coating is black with a blue or brown tint.
	A gray tint in the inner corners, recesses and holes of complexly shaped parts is not a rejection feature.
Thickness	In accordance with the requirements of the design documentation
Porosity	No more than three through pores per 1 cm 2 of surface area and 1 cm of edge length, unless otherwise indicated in the design documentation *.
	The porosity of milk chrome less than 24 microns thick, protective and decorative two-layer less than 21 microns thick and wear-resistant less than 40 microns thick is not standardized *.
	The number of pores on the surface of the microporous coating (X mp) when evaluated using optical microscopes with a magnification of at least 100 × should be at least 10,000 per cm 2.
	The porosity of black chromium is not standardized.
	On the surface of the chrome microcrack coating (X mt) there must be at least 250 cracks at a length of 1 cm in all directions, forming a network of cracks
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product
Functional properties	Coating hardness - according to GOST 9.303-84
Protective properties	Also
	When testing the phosphate coating, the color of the test solution droplet shall not change to black within the specified time.

* Requirements apply to the coating on steel parts.

(Amendment. IUS 1-1991)

Table 5

Tin plating and tin alloy plating

Indicator name	Coating requirements
Appearance	The color of fused and unmelted coatings ranges from light gray to gray. The melted coating is shiny. Uneven gloss on one part is allowed.
	The color of the coating with a tin-nickel alloy is light gray. Pink and purple shades are allowed.
	The color of the coating with a tin-lead alloy is from light gray to dark gray. The shade is not standardized.
	The color of the tin-bismuth coating is from light gray to gray.
	Metal beads that do not interfere with assembly and do not affect the functional properties of the coating are not a rejection sign.
Thickness
Chemical composition	Tin coatings intended for use in contact with food must contain no more than 0.1% lead and no more than 0.025% arsenic
	Mass fraction of tin in alloy coatings:
	O-H (65) - from 50 to 70%;
	O-S (60) - t 50 to 70%;
	O-C (40) -30 to 50%;
	O-C (12) - from 8 to 15%.
	Mass fraction of bismuth in the O-Vi (99.8) alloy coating from 0.2 to 4.0%
Porosity*	Not more than three through pores per 1 cm 2 of surface area and 1 cm of edge length, unless otherwise indicated in the design documentation.
Porosity*	With a coating thickness of 6 microns or less, it is not standardized
Functional properties
Protective properties	Also

* Requirements apply to the coating on steel parts.

Table 6

Hot tin and tin-lead alloy coatings

Indicator name	Coating requirements
Appearance	Tin plating color is from light gray to gray, tin-lead alloy plating color is from gray to dark gray. The coating is glossy or matte, smooth. The gloss level is not standardized.

	slight sagging and unevenness of the coating thickness, which do not interfere with the soldering or work of the part;
	spatter and metal drops that are firmly adhered to the base, do not interfere with the work of the part, on non-working and working (according to the sample) surfaces, as well as on surfaces on which coating is not provided, except for sliding surfaces;
	dark spots on the coating on the inner surfaces of blind holes;
	slight tuberosity along the entire length of the wire and a depression from the contact of the wire with the guide roller, not reaching the base metal;
	non-uniformity of the color of the coating.
	Not allowed:
	rough nodules;
	dark spots, dots, white or brown indelible film;
	cracks, coating delamination, uncovered areas;
	solder splashes on work surfaces coated with precious metals (gold, silver, palladium, etc.);
	acid flux residues
Thickness	Not standardized
Chemical composition	The chemical composition of coatings with tin-lead alloys must correspond to the chemical composition of the main components of solders in accordance with GOST 21930-76 and GOST 21931-76
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 7

Silver plated and silver-antimony alloy plated

Indicator name	Coating requirements
Appearance	The color of the silver plating and the silver-antimony alloy plating is silvery-white.
	The color of the silver coating made from electrolytes with brightening additives and the silver chromated coating is white with a yellowish tinge.
	The color of the chemical silver plating is white.
	The color of the blackened silver coating is from a dark gray child.
	The following signs are not considered defective:
	dark spots, stripes and discoloration in blind holes, grooves, in concave areas of parts of complex configuration;
	darkening of the coating during storage before assembly and color change from light pink to light brown after heat treatment, pressing into plastic, provided that functional properties are retained
Thickness	In accordance with the requirements of the design documentation
Chemical composition	Mass fraction of antimony in the coating with Sr-Su alloy from 0.4 to 2%
Porosity
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 8

Gold plating and gold alloy plating

Indicator name	Coating requirements
Appearance	Gold plating color from light yellow to dark yellow
	The color of the coating with gold-nickel alloy is from light yellow to yellow.
	Coating color with gold-cobalt alloy from orange-yellow to yellow
Thickness	In accordance with the requirements of the design documentation
Chemical composition	Mass fraction of nickel in the coating with Zl-N alloy and mass fraction of cobalt in the coating with Zl-Ko alloy - in accordance with the requirements of GOST 9.303-84
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 9

Palladium plated

Indicator name	Coating requirements
Appearance	Coating color from light gray to gray with a yellow tint.
Appearance	Single dark spots, iridescent shades from light brown to violet, formed during heating, provided that the functional properties are preserved
Thickness	In accordance with the requirements of the design documentation
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 10

Rhodium plated

Indicator name	Coating requirements
Appearance	Coating color light gray with a blue tint
Thickness	In accordance with the requirements of the design documentation
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product.

Table 11

Chemical oxide coating on steel and cast iron

Indicator name	Coating requirements
Appearance	Coating color Chem. Ox (including after oil impregnation) on parts made of carbon and low-alloy steels, black with a blue tint. On parts obtained by casting, a black coating with a gray or brown shade is allowed.
	The color of the coating on high-alloy steel parts is from dark gray to dark brown with a cherry tint.
	The color of the coating on parts made of cast iron and silicon alloyed steels is from light yellow to dark brown.
	The color of the coating on high carbon tool steel parts is black with a gray tint
	Non-uniformity of color and shade is allowed on parts that have undergone local hardening, welding, carburizing, peening and other machining; red tint of coatings on small profiled parts and between coils of springs with a small pitch, light gray - on sharp edges of parts
Thickness	Not standardized
Protective properties	On the Khim.Oks coating after testing for a specified time, there should be no spots of contact released copper.
Protective properties	On the coating Chem.Ox. prm after the tests there should be no foci of corrosion, with the exception of sharp edges and ends of the springs, on which no more than three points of corrosion are allowed per 1 cm 2 of the surface area and per 1 cm of the edge length

Table 12

Chemical passivation coating
on corrosion-resistant steels.

Indicator name	Coating requirements
Appearance	Coating color Chem.Pas. must match the color of the metal being processed.
	The following signs are not considered defective:
	iridescent shades, depending on the steel grade, including in the places of welding, bending;
	slight darkening;
	traces of mechanical finishing;
	black inclusions in the form of separate small dots
Thickness

Table 13

Chemical oxide and anodic-oxide coatings on copper and its alloys

Indicator name	Coating requirements
Appearance	Coating color Chem.Ox and An.Ox from dark red with a brown tint to black with a blue tint

	traces of mechanical finishing of the base metal surface;
	partial lack of coverage on sharp edges;
	darkening between coils of springs with a small pitch.
	The color of the Chem.Pas coating must correspond to the color of the processed metal.
	The following signs are not considered defective:
	rainbow shades;
	darkening of the coating between the coils of the springs with a small pitch;
	non-uniformity of the varnish film in color and varnish drips after varnishing, which do not interfere with assembly and do not affect the performance of the product
Thickness	Not standardized
Protective properties	When tested on a Chem.Pas coating, there should be no change in the color of the drop to blue before the specified time has elapsed.

Table 14

Chemical oxide coating on aluminum and its alloys

Indicator name	Coating requirements
Appearance	Coating color Chem.Ox from gray-blue to dark blue or from light blue to green or yellow
	on alloys of grades D16, D1, D24F - greenish-blue with or without rainbow shades;
	on cast alloys - blue-gray with black and brown stains.
	The color of the coating Chem.Pas corresponds to the color of the base metal.
	Coating color Chem.Ox.e from colorless to light blue or light yellow; golden yellow to brown with iridescent shades on wrought alloys; gray with yellow and brown streaks on cast alloys.
	The following signs are not considered defective:
	dark and light stripes in the direction of rolling, soldering and welding points;
	darkening on high-temperature brazed parts;
	separate stains from chrome salts around the holes, in the places of contact of parts with the device, in the places of conjugation of one-piece assembly units, around the pores and places of inclusions allowed by the normative and technical documentation for casting;
	revealing the structure of the base metal
Thickness	Not standardized
Protective properties
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 15

Anodic oxide coating on aluminum and its alloys

Indicator name	Coating requirements
Appearance	The color of An.Ox coating is from light gray to dark gray, on parts made of cast alloys from light gray to dark brown. The shade is not standardized.
	The color of the painted coating must match the color of the sample. The shade is not standardized. On multicomponent and cast alloys, reflections of various tones are possible.
	Coating color An.Ox.chrom from milky to gray, rainbow shades are possible.
	Coating color An.Ox.nkhr from light green to yellow-green, on multicomponent and casting alloys from gray to dark gray. The shade is not standardized.
	The following signs are not considered defective:
	dark points and spots as a result of revealing the heterogeneity of the base metal structure;
	dark and light stripes in the direction of rolling, places of welding, lapping, work hardening, places where the cladding layer is absent;
	yellow spots from chromium salts around the holes, in the places of contact of the part with the device, in the places where one-piece assembly units are mated, around the pores and places of inclusions allowed by the normative and technical documentation for casting.
	The color of the coating An.Ox.tv is from light gray to black, yellow-green shades are allowed.
	Coating color An.Ox.es from light yellow to dark brown or from light gray to dark gray.
	The color of the coating An.Ox.tv and An.Ox.eiz after filling with chromates from yellow-green to brown-black.
	The presence of microcracks on the An.Ox.ex coating is not a rejection sign if they do not affect the functional properties.
	The color of the coating An.Ox.emt is from light gray to dark gray, depending on the alloy used, enamel-like. The shade is not standardized.
	The color of the painted coating must match the color of the sample
	Coating color Anotsvet light brown, gray-blue, blue-black, golden, golden-bronze, bronze, gray-brown.
	A lighter tone is allowed on the inner surfaces of parts
Thickness	In accordance with the requirements of the design documentation
Coating filling quality	After testing, the weight loss of the sample should not exceed 20 mg / dm 2 for products intended for operation in an open atmosphere, and 30 mg / dm 2 for products intended for use in an enclosed space.
Coating filling quality	After the tests, the coating should not be stained or may be slightly stained!
Completeness of flushing	The specific electrical conductivity of water after washing the coating An.Ox.eiz should not exceed three times its initial value
Protective properties	When tested, there shall be no change in the color of a drop of the test solution before the specified time has elapsed.
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 16

Anodic oxide coating on titanium alloys

Indicator name	Coating requirements
Appearance	Coating color Anotsvet from blue to blue, pink, green, yellow. The shade is not standardized.
	Traces of mechanical finishing of the surface of the base metal are not a rejection sign.
	Coating color An.Ox from light gray to dark gray
Thickness	Not standardized
Functional properties	In accordance with the requirements of the design and (or) regulatory and technical documentation for the product

Table 17

Chemical oxide and anodic oxide coatings
on magnesium and magnesium alloys

Indicator name	Coating requirements
Appearance	Coating color Khim.Oks from straw yellow to dark brown or black.
	Coating color Chem.Phos from light gray to dark gray.
	Coating color Anosvet is yellow, green or gray-black. The shade is not standardized.
	The following signs are not considered defective:
	tarnish colors; stains resulting from re-oxidation; point areas of metal without coating around the pores; gray spots with smearing deposits on the ML-5 alloy;
	black spots on machined surfaces resulting from local heating of the metal during machining
Thickness	Coating thickness Chem.Ox is not standardized, An.Ox - in accordance with the requirements of design documentation

Table 18

Phosphate coating on steel and cast iron

Nameindicator	Coverage requirements
Appearance	Coating color from light gray to black, after impregnation with oil, emulsion or after hydrophobization from dark gray to black.
	The following signs are not considered defective:
	heterogeneity of crystal sizes in areas of local hardening, welding, work hardening, various surface roughness in decarburized areas;
	white bloom, removed by wiping;
	deposits of phosphate sludge on non-working surfaces;
	traces of a copper electrode on parts welded with spot or roller welding;
	stains, streaks and streaks after wiping with an emulsion, varnish or after hydrophobization, which do not interfere with assembly and do not affect the performance of the product;
	yellow spots from chrome salts around holes, places of contact of a part with a device and places of conjugation of assembly units, spots around pores and places of inclusion allowed by regulatory and technical documentation for casting
Coating mass per unit surface area	Coating mass per unit of surface area before impregnation - not less than 5 g / m 2; on a surface with roughnessR a 1.25-0.63 microns, it is allowed to reduce the coating mass per unit surface area in accordance with the requirements of the normative and technical documentation.
Coating mass per unit surface area	Coating mass per unit surface area before applying paint and varnish in accordance with the requirements of GOST 9.402-80
Structure	The coating intended for paintwork must have a microcrystalline structure.
Protective properties	When tested in accordance with GOST 9.302-88, the color of the drop should not change during the specified time or after the test, there should be no foci of corrosion on the coating, with the exception of sharp edges, mating points of one-piece assembly units, where no more than three pinpoint foci of corrosion per 1 cm 2 are allowed surface area and 1 cm of edge length
Oil absorption	Not less than 2.0 g / m 2
Completeness of flushing	The specific electrical conductivity of water after washing the coating intended for the paintwork should not exceed three times its initial value.

Table 19

Chemical oxide chromate and phosphate coatings on zinc alloys

Indicator name	Coating requirements
Appearance	Coating color Khim.Oks.chrom greenish-yellow with iridescent shades; in the presence of a copper alloy, the color of the coating is gray-blue; Coating color Chem.Phos from light gray to gray.
	The following signs are not considered defective:
	a matte surface and a weakening of the color intensity of the chromate coating on parts after heat treatment, hydro-sandblasting, tumbling and etching;
	a darker or lighter shade of chromate coating in holes and grooves, on internal surfaces and on concave areas of parts of complex configuration, at the interface of one-piece assembly units, on sharp edges, corners, at points of contact with the device, between coils of springs with a small pitch;
	matte stripes around the holes
	single mechanical damage of chromate coating not more than 2%
Thickness	Not standardized