GB/T 13346-2012 Metallic and other inorganic coatings Treated cadmium plating on iron and steel GB/T13346-2012 Standard compressed package decompression password: www.bzxz.net
This standard specifies the requirements for treated cadmium electroplated coatings on iron and steel. It includes information provided by the purchaser to the electroplater and includes requirements for the coating and heat treatment before and after electroplating. This standard does not apply to cadmium electroplated coatings on unformed sheets, strips or wires; cadmium electroplated coatings on closely wound springs; or uses other than protection, self-lubrication, ductility, electrical conductivity and low contact resistance. This standard does not specify requirements for the surface condition of the base metal before cadmium plating. The thickness of the coating on threaded parts will be limited by dimensional requirements such as thread grade and fit.
This standard was drafted in accordance with the rules given in GB/T1.1-2009.
This standard replaces GB/T13346-1992 "Cadmium electroplating on metal coatings steel". Compared with GB/T 13346-1992, the main changes of this standard are as follows:
——— The requirements for treatment are added to the original name;
——— The terms such as main surface, local thickness and minimum local thickness are deleted, and abbreviated terms and symbols are added (see 3.2 and 3.3);
——— Chapter 4 Base Metal, Chapter 6 Coating Representation Method, Chapter 7 Coating Thickness Series, Chapter 8 Heat Treatment, Chapter 10 Requirements for Coatings and Chapter 11 Test Methods in the 1992 edition are deleted;
——— Marking (see Chapter 5) and requirements (see Chapter 6) are added;
——— The provisions for chromate conversion coating and other post-treatment are added (see Appendix A);
——— The measurement of average coating thickness on small parts is added (see Appendix B);
——— The data on corrosion resistance, cleaning, drying, bulk parts processing and dyeing of chromate conversion coating are added (see Appendix C).
This standard adopts the translation method equivalent to ISO2082:2008 "Metallic and other inorganic coatings - treated cadmium coatings on iron and steel".
For Chinese documents that have a consistent correspondence with the international documents normatively referenced in this standard, see Appendix NA.
This standard has made the following editorial changes:
Informative Appendix NA is added, which contains Chinese documents that have a consistent correspondence with the international documents normatively referenced in this standard.
This standard is proposed by the China Machinery Industry Federation. This
standard is under the jurisdiction of the National Technical Committee for Standardization of Metallic and Non-metallic Coatings (SAC/TC57).
The main drafting units of this standard are: Wuhan Institute of Materials Protection, Ma'anshan Dingtai Rare Earth New Materials Co., Ltd., Tiantang Umbrella Industry Group Co., Ltd., Tongxiang Tongde Electric Power Accessories Co., Ltd., Tongxiang Tiesheng Line Equipment Co., Ltd., and Wuhan Kangjie Technology Co., Ltd. The main drafters of
this standard are: Deng Rizhi, Zhang Dezhong, Jia Jianxin, Shi Zhimin, Liu Jilu, Gong Dashu, Shen Hongwei, Chu Qifeng, Li Weijiang, Li Xiaodong, Yu Hui, Li Xia. The previous versions of the standards replaced by this standard are: ———GB/T13346—1992. The following documents are indispensable for the application of this document. For all dated referenced documents, only the dated version applies to this document. For all undated referenced documents, the latest version (including all amendments) applies to this document. ISO1463 Metallic and oxide coatings—Measurement of coating thickness— Microscopical method ISO2064 Metallic and other inorganic coatings—Definitions and conventions concerning the measurement of thickness ISO2080 Metallic and other inorganic coatings—Surface treatment—Vocabulary|| tt || ISO2177 Metallic coatings— Measurement of coating thickness—Coulometric method by anodic dissolution ISO2178 Non-magnetic coatings on magnetic substrates—Magnetic method magnetic substrates—Measurement of coating thickness—Magnetic method) ISO2819 Metallic coatings on metallic substrates—Electrodeposited and chemically deposited coatings—Review of methods available for testing adhesion ISO3497 Metallic coatings—Measurement of coating thickness—X-ray spectrometric methods ISO3543 Metallic and non-metallic coatings—Measurement of coating thickness—Beta-ray backscattering method

ICS25.220.40
National Standard of the People's Republic of China
GB/T 13346-2012/IS0 2082.2008 replaces GB/T 13346--1992
Metallic and other inorganic coatings-Electroplated coatingsof cadmium wiih supplementary treatments on iron or steel(ISO2082.2008.IDT)
Issued on 2012-11-05
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implementation on 2013-03-01
This standard was drafted according to the plan given in GB/T 1.1-2009. GB/T 13346—2012/ISO 2082:2008 This standard replaces GB/T 13346:-1992 "Cadmium electroplating on metallic coatings of steel". Compared with GB/T 13346-1992, the main changes of this standard are as follows:
The requirements for treatment are added to the original name; the terms such as main surface, local thickness, minimum local thickness are deleted, and abbreviations and symbols are added (see 3.2 and 3.3); Chapter 4 Base Metal, Chapter 6 Coating Representation Method, Chapter 7 Coating Thickness Series, Chapter 8 Heat Treatment, Chapter 10 Requirements for Coating, and Chapter 11 Test Methods in the 1992 version are deleted; marking (see Chapter 5) and requirements (see Chapter 6) are added; the provisions for chromate conversion coating and other post-treatment are added (see Appendix A); the measurement of the average thickness of the coating on small parts is added (see Appendix B); the information on the corrosion resistance, cleaning, drying, bulk parts processing and dyeing of lead conversion coating is added (see Appendix C). This standard uses the translation method equivalent to ISO2082:2008 "Treatment of Electroplated Coatings on Metallic and Other Inorganic Coverings Iron and Steel".
For Chinese documents that have a consistent correspondence with the international documents normatively referenced in this standard, see Appendix NA. This standard has made the following editorial changes:
Informative Appendix NA has been added, which contains Chinese documents that have a consistent correspondence with the international documents normatively referenced in this standard. This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the National Technical Committee for Standardization of Metallic and Non-metallic Coverings (SAC/TC57). The main drafting units of this standard are: Wuhan Institute of Materials Protection, Ma'anshan Dingxishi New Materials Co., Ltd., Datong Umbrella Group Co., Ltd., Tongxiang Tongde Electric Power Accessories Co., Ltd., Tongxiang Tiesheng Line Equipment Co., Ltd., and Wuhan Kangjie Technology Co., Ltd. The main drafters of this standard are: Deng Rizhi, Zhang Dezhong, Jia Jianxin, Shi Zhimin, Liu Jilu, Gong Dashu, Shen Hongwei, Chu Qifeng, Li Weijiang, Li Xiaodong, Yu Hui, and Li Xia.
The previous versions of the standards replaced by this standard are: CGB/T 13346—1992.
GB/T 13346--2012/ISO 2082:2008Introduction
Electroplating is commonly used for the corrosion protection of steel. Since cadmium is an anode that corrodes sacrificial metals, ferrous metals can be protected from corrosion even in the presence of holes or pits in the electroplated layer. Traditionally, alkaline cadmium solutions have been used for cadmium plating on steel. In recent years, sulfuric acid, neutral fluoride and acidic fluoride solutions have been increasingly used for cadmium electroplating due to environmental concerns and related regulations.
Since the surface condition of the metal substrate directly affects the appearance and performance of the electroplated layer, the relevant partners should reach an agreement on the standard of the surface condition of the metal substrate. Cadmium is a highly toxic metal. Therefore, due to health, safety and environmental considerations, the use of cadmium in non-essential situations is strictly restricted. Nevertheless, due to the unique properties of cadmium coatings, such as corrosion resistance, self-lubricity, ductility, electrical conductivity and low contact resistance, electroplating is irreplaceable in some extremely important applications, especially those related to aviation. The corrosion resistance of electroplated cadmium layers and their tendency to dull after treatment can be improved by chromium conversion coatings or other post-treatment of the coating or conversion coating.
Chemical conversion coatings that do not contain hexavalent chromium are becoming increasingly popular in commercial applications. In appearance, these substitutes may differ from chemically treated coatings containing hexavalent chromium. Other chromium-free conversion coatings are also commercially available. Substitutes must meet the requirements for corrosiveness in this standard. Industry
GB/T13346-2012/IS0 2082:2008 Metallic and other inorganic coatings
Treatment of cadmium coatings on steel
Note 1: Vapors are highly toxic. Therefore, during heat treatment, reliable precautions should be taken to ensure the safety of operators. The possibility of danger from cadmium vaporization during welding or other heating processes should also be noted. Due to its toxicity, cadmium cannot be used as a coating for containers that come into contact with food, beverages or any household items.
Note 2: This standard may endanger health if adequate safety measures are not taken during its use. This standard does not address any health, environmental, safety or legal issues related to its use. The supplier and purchaser of this standard are responsible for establishing appropriate health, safety and environmental practices and taking appropriate actions to comply with national or international rules and regulations. Compliance with this standard does not legally grant immunity from the user's obligations.
1 Scope
This standard specifies the requirements for cadmium electroplated coatings on steel after processing. It includes information to be provided by the purchaser to the electroplater and includes the requirements for heat treatment before and after electroplating.
This standard does not apply to cadmium electroplated coatings on unformed sheets, strips or wires; cadmium electroplated coatings on tightly wound springs: or uses other than protection, self-lubrication, ductility, conductivity and low contact resistance. This standard does not specify requirements for the surface condition of the base metal before electroplating. The coating thickness of threaded parts will be limited by the dimensional requirements such as thread grade and fit. 2 Normative references
The following documents are essential for the application of this document. For all references with dates, only the versions with dates apply to this document. For all undated references, the latest versions (including all amendments) apply to this document. ISO1463Metallic and oxide coatings—Measurement of coating thick- Microscopic methodISO2064Metallic and other inorganic coatings—Delinitions and conventions concerning the measurement of thicknessISO2080Metallic and other inorganic coatings—Surface treatment—VocabularyISO2177Metallic coatings—Measurement of coating thickness'\ Coulometric nethod by anodic dissolutionISO2178Non-magnetic coatings on magnetic substrates—Magnetic methodISO2819Metallic coatings on metallic substrates--Flcctrodepasited and chemically deposited coatings-Review of mcth-ods available for testing adhesionISO3497Metallic coatingsMeasurement of coating thickness--X-ray spectrometric methodsISO 3543Metallic and non-metallic coatings--Measurement of coating thickness--Beta backscattering methodISO3613Chromate conversion coatings on zinc, cadmium, aluminum-zinc alloys and zinc-aluminum alloys ISO3892Conversion coatings on metallic materials - Measurement of coating mass per unit area - Gravimetric methodsISO4518Metallic coatings - Measurement of coating thickness - Profilometry methodISO4519Electrodeposited metallic short coatings and related finishes - Sampling procedures for inspection by atiributesISO9587Metallic and other inorganic coatings - Pretreatment of steel to reduce the risk of hydrogen embrittlementISO 9588 Metallic and other inorganic coatings - Post-coating treatments of iron or steel to reduce the risk of hydrogen embrittlement - ISO 10289 Methods for corrosion testing of metallic and inorganic coatings on metallic substrates Rating of testspecimens and manufactured articles subjected to t corrosion tests ISO 10587 Metallic and other inorgauic coatings - Test for residual etnbritileneut in both fmelllic-coated and uncoated crnally-thrcaderl artieles and rads-.Inrlinerl wedge ISO 15724 Electrochemical measurement of diffusible hydrogen evolution in steels - Barnacle electrode method ISO 27830 Metallic and other inorganic coatings Guidelines for specifying metallic and inorganic coatings ASTM BlI 7 Standard Practice for Operating Salt Spray (Fog) Apparatus
3 Terms, definitions, abbreviations and symbols
3.1 Terms and definitions
The terms and definitions given in ISO 2080 and ISO 2064 apply to this document. 3.2 Abbreviations
C Color conversion coating;
D Opaque chromate conversion coating;
ER Heat treatment to eliminate hydrogen embrittlement:
NM Non-metallic material:
PL Plateable plastic material;
SR Aging heat treatment:
T2 Organic sealant.
3.3 Symbols
Cd Chemical symbol for cadmium;
Fe Chemical symbol for iron.
4 Information required to be provided by the supplier
4.1 Necessary information
GB/T13346—2012/ISO2082.2008 The following information should be provided to the supplier in writing, for example, in the contract, order or engineering drawing: a) Reference and specification of this standard GB/T13346 (see Chapter 5); b) Marking of important surfaces, for example, markings specified in drawings or samples; if the nature, surface condition and surface finish of the substrate will affect the appearance of the coating (see Chapter 1)! unavoidable surface defects such as machining marks (see 6.1); d) the final requirement, for example, bright, matte or other fine finish, preferably compared with a verified standard sample (see 6.1); e) the type of chromate conversion coating or auxiliary treatment (see 6.3 and Annex A); whether to use chromate conversion coatings and alternative conversion coatings and t) other auxiliary treatments (see Table A.2) or protective coatings such as paint on chromate coatings, etc., depends on the specific requirements of the purchaser, g) requirements for thickness, adhesion and accelerated corrosion tests (see 6.2, 6.1, 6.5 and Annex B); h) tensile strength of parts before heat treatment and after electroplating and requirements (see 6.6 and 6.): If there is a conflict between the sampling method, acceptance criteria and any other inspection requirements, ISO 4519 shall prevail (see Clause 7). i
4.2 Additional Information
The following additional information should also be provided to the supplier: a) any special requirements or restrictions on the product coating (see references); b) any other requirements, such as testing or evaluation areas for complex-shaped products. 5 Marking
5.1 Overview
Marking should appear on engineering drawings, purchase orders, contracts or detailed product specifications. The marking provisions should be arranged in the following order: base metal, aging treatment requirements, bottom coating thickness and type, surface coating thickness, post-heat treatment requirements, conversion coating type and/or post-treatment (see references).
5.2 Marking specifications
The marking specifications shall include the following:
a) the term "electroplated layer";
b) the standard number of this standard GB/T13346; hyphen;
the chemical symbol of the substrate, Fe (iron or steel), according to the standard name of the substrate; e)
slash ();
if necessary, mark SR after the slash (/); g)
the chemical symbol of cadmium, "Cd";
h) the minimum thickness of the coating expressed in μm after the slash (/); 1)
if necessary, mark ER after the slash (/); j
if necessary, indicate the type of chromate conversion coating with a code after the slash (/) (see Appendix A) k)
if necessary, any post-treatment method specified by code (see Appendix A). 3
GB/T 13346—2012/SO 2082200B Slashes () are used to separate the data between different treatment sequences. Double slashes or single slashes indicate that a step in the treatment process is not required or has been omitted (see ISO 27830). If a post-treatment other than chromate conversion coating is added to the 25 μm thick radiation coating, it is expressed as Fe/Cd25/X/Y. Note:
represents one of the chromate conversion coating codes given in Table A.1; Y——represents one of the codes given for other auxiliary coatings in A.2. 5.3 Designation of heat treatment requirements|| tt||The heat treatment requirements shall be specified as follows: SR indicates stress reduction heat treatment before electroplating / ER indicates heat treatment after electroplating to eliminate hydrogen embrittlement: the lowest temperature in brackets is expressed in degrees Celsius (℃); the duration of heat treatment is expressed in hours (h). For example: SR(210)1 ​​indicates a potential treatment for stress reduction at 210℃ for 1 hour. 5.4 Examples
The following are examples of specifying coatings,
Example: Electroplating of cadmium and color passivation film (C) with a thickness of 12μⅡ on iron or steel: Electroplating layer GB/T 13346-Fe/Cd12/C
Example 2: Electroplating of a pot with a thickness of 25 μIm on iron or steel I, after electroplating at 190℃ for 8 h Heat treatment to eliminate hydrogen embrittlement, marked as ER(190)8, adding opaque chromate conversion film (I) and organic sealant sealing post-treatment (T2): Electroplating layer GB/T13346-Fe/Cd25/ER(190)8/D/T2 Example 3: Same as Example 2, but before electroplating, heat treatment with hydrogen reduction for 3h to eliminate stress is performed at 200C, marked as SR(200)3: Electroplating layer GB/T13346-Fe/SR(200)3/Cd25/ER(190)8/D/T2—6 Requirements
6.1 Appearance
Although this standard does not make special provisions for the surface finish or surface roughness of the substrate before electroplating, the surface condition of the substrate also determines the appearance of the electroplated layer (please refer to the surface treatment literature). There should be no visible post-plating defects such as blistering, pitting, roughness, cracks or missed plating areas on the important surfaces of the electroplated parts (except those caused by defects in the substrate metal). The areas of contact marks on the plated parts that cannot be avoided shall be determined by agreement between the parties concerned (see 4.1). The plated parts shall be free of damage to the net H and, unless otherwise specified by the purchaser, the cadmium coating shall be bright. If necessary, the required finish shall be provided or approved by the purchaser in accordance with the sample [see 4.1e)].
6.2 Thickness
The thickness of the coating shall be the minimum thickness within the specified range. The minimum local thickness of the coating shall be measured on the part of the main surface that can be contacted by a ball with a diameter of 20 mm, unless otherwise specified by the purchaser (see 4.1 and 4.2). The method for measuring the thickness of cadmium coatings on steel is specified in ISO 2177, ISO 2178, ISO 1463, ISO 3497, ISO 3543 and ISO 4518.
In case of dispute, ISO 2177 stipulates that the measurement area shall be greater than or equal to 100 mm. If the surface area of ​​the part in question is less than 100 mm, the minimum thickness shall be taken as the minimum of the average thickness determined by the method specified in Annex B. Before measuring according to the method specified in ISO 2177, the chromate conversion coating shall be removed with a very soft abrasive, for example, lead oxide paste. In the presence of a conversion coating, the measurement result will be slightly reduced. GB/T 13346-2012/IS02082:2008 If the coating surface is rough, the results of the microscopic method (ISO 1463) and the profilometer method (ISO 4518) may be unreliable, and the results obtained by the measurement method are biased when compared with a smooth coating of the same mass per unit area. Table 1 provides the requirements for the thickness of the corrosion protection layer under various conditions of use. 6.3 Conversion coating and other post-treatment
At the request of the purchaser, the conversion coating may be omitted or replaced by another conversion coating [see 4.1f) ii. Annex A specifies the code for chromate conversion coating and other auxiliary coatings.
Conversion coatings that do not contain hexavalent chromium, such as trivalent chromium or chromium-free conversion coatings, are commercially available and comply with this standard. All available chromate conversion coatings, alternative conversion coatings or substitutes (except phosphate coatings) shall comply with this standard for use under corrosive conditions. Conversion coatings containing trivalent chromium are applicable to all codes in Table A.1. However, the appearance of the alternative conversion coatings may differ from that of hexavalent chromium conversion coatings. Here, Tables 1, 2, A.1, A.2 and C.1 reflect the requirements of this standard and have been generally accepted by metal finishing manufacturers, product processors and purchasers worldwide in practical use for decades. 6.4 Adhesion of radiant coatings and chromate conversion coatings Cadmium coatings shall be tested on the ground base metal E. as specified in ISO 2819. Chromate conversion coatings shall be tested for adhesion in accordance with ISO 3613.
6.5 Accelerated corrosion tests
Danger—Vapours are highly toxic by inhalation. During heat treatment, adequate precautions shall be taken to ensure the safety of operators. Attention should also be drawn to the hazards arising from welding or heating and other processes in which the possibility of cadmium vaporization exists. Due to its toxicity, cadmium should not be used as a coating on containers that come into contact with food, beverages or any household items: 6.5.1 Neutral Salt Test Required
The results of the neutral salt spray (VSS) accelerated test in accordance with the ASTM B117 Salt Spray Test Equipment Specification are given in Tables 1 and 2. The residual red corrosion products (see Table 1) or white corrosion products (see Table 2) on the test surface are acceptable when examined by the naked eye or corrected vision.
If salt treatment is performed, Tables 1 and C, 1 give the minimum thickness of the required coating. The thickness of the cadmium coating depends on the severity of the service conditions to ensure the required corrosion resistance. For example, the sensitive coating named Fe/Cd5 is recommended only for dry indoor environments. For environments with severe service conditions, it is necessary to increase the thickness of the pot coating to improve the corrosion resistance and specify the requirements for the use conditions of the radiant coating (see Table C. 1).
It is recommended to use the classification codes Fe/Cd12 and Fe/Cd25 to represent the colored chromate conversion film of the cadmium coating. The time and results of the artificial atmosphere corrosion test may not be directly related to the actual service life of the coating. Therefore, the results obtained from the test cannot be regarded as all direct guidance for the corrosion resistance of the coating in the test environment in which these coatings can be used. Table 1 Corrosion resistance of cadmium plus chromate conversion coating Neutral salt spray corrosion Base metal corrosion (red rust) Start time Coating specification
(local)
Neutral salt spray test timebzxZ.net
GB/T13346—2012/1S020822008
Coating specification
(local)
Cd12/A
Cd12/F||t t||Cd12/C
Cd12/D
Cu25/A
Cd25/F
rd25/C
Cd25/D
Table 1 (continued)
Neutral salt penetration test time
Table 2 Corrosion resistance of chromate conversion film on cadmium coating Neutral lack of fog test time
Chromium salt conversion film code.
See Appendix A.
6.5.2 Corrosion rating
After testing, the evaluation of the sample shall comply with the provisions of ISO 10289. The acceptance evaluation shall be specified by the purchaser. 6.6 Heat treatment for stress relief before metal cleaning and electroplating When the purchaser specifies that the ultimate tensile strength of the steel part is equal to or greater than 1000 MPa (including stresses caused by machining, grinding, cold forming or straightening operations), a stress relief heat treatment shall be carried out before metal cleaning and intermediate plating. The steps and types of aging heat treatment shall be specified by the purchaser or carried out by the purchaser in accordance with the steps and types specified in ISO 9587. When heat treatment for stress relief before electroplating or for hydrogen embrittlement relief after electroplating is specified (see 6.7), the heat treatment time and temperature include the specified coating as in 5.3 and 5.1.
Before electroplating, oxidation and rust on the steel surface should be removed. For high-strength steel (equal to or greater than 1000 MPa), non-electrolytic alkaline, anodic alkaline cleaners and mechanical cleaning methods should be preferred. Cleaning methods that may cause hydrogen embrittlement during production should be avoided (see references).
6.7 Heat treatment to eliminate hydrogen embrittlement after electroplating
According to the purchaser's specification, steel parts with an ultimate tensile strength equal to or greater than 1 000 MPa and surface hardened parts should be heat treated to eliminate hydrogen embrittlement in accordance with the steps and categories specified in ISO9588 GB/T 13346-—2012/ISO 2082:2008 When stress relief heat treatment before electroplating (see 6.6) or hydrogen embrittlement relief heat treatment after electroplating is specified, the heat treatment time and temperature including the specified coating are as shown in 5.3 and 5.4. Unless otherwise specified by the purchaser, the effectiveness of the heat treatment to eliminate hydrogen embrittlement shall be determined in accordance with ISO 10587 Residual hydrogen embrittlement test for bolts and screws with grain coating and without metal coating - inclined wedge method and ISO 15724 Electrochemical measurement of diffusible hydrogen in steel
Barnacle electrode method.
All heat treatments to eliminate hydrogen embrittlement shall be carried out before the chromate conversion coating treatment. 7 Sampling
In accordance with ISO 4519, samples shall be randomly selected from the inspection batch. According to the sampling criteria of ISO 4519, the samples inspected shall comply with the provisions of this standard and be classified as qualified or unqualified. If other forms of sampling are selected, see 4.1i)1. Random samples shall be selected from the samples to be tested that meet the requirements of this standard. Appendix A of GB/T13346---2012/ISO2082:2008
(Special Appendix)
Overview of provisions for chromate conversion coating and other post-treatments
Chromate conversion treatment solutions are usually acidic and contain hexavalent chromium or trivalent chromium salts and other salts that can change the appearance and hardness of the conversion coating. Cadmium coatings can be treated with different solutions to obtain bright, iridescent, olive-edge and black passivation films. The iridescent film can also be faded in alkaline or phosphoric acid solutions to obtain a transparent film. The appropriate coating guidance provided in Table C.1 is required. Table A.1 gives the approximate surface density (mass per unit area) of various types of chromate conversion coatings measured in accordance with IS(3892). Table A1 Chromate conversion coating types, appearance and surface density Class
Opaque
Typical appearance
Transparent, light blue
Yellow rainbow
Olive green
Note 1: The description of chromate coatings in this table does not necessarily refer to improved adhesion of paints and varnishes. Note 2: The chromate coatings in this table may or may not contain hexavalent ions A.2 Enclosed
Capsule surface density
Pa/(g/m*)
0. 5<<1. 5
0. 5spas1. 0
In order to provide better corrosion protection, the chromate conversion coating can be sealed with an organic or inorganic product. Sealing also improves the temperature resistance of the chromate conversion coating. The conversion coating can be sealed by dipping or spraying with a polymer aqueous solution. A similar treatment scheme is to add a suitable organic substance to the chromate solution.
Post-treatment of the conversion coating
If the conversion coating needs to be post-treated, the treatment type and code are shown in Table A.2 As shown. Qiu A.2 Post-treatment of conversion coating
Type of treatment
Use paint, clear, powder coating or similar coating materials Use organic drive inorganic sealant
Use organic dye
Use grease, oil or other lubricant
Use wax
B.1 Materials
Appendix B
(Normative Appendix)
Average thickness of coating on small parts
Note—The sample preparation process should be carried out in a cabinet or fume hood. Important matters: This appendix stipulates that the parts after deplating shall not be reused. B.1.1 Suitable desensitization solution: including 300g/1. Ammonium nitrate (NH4NO,), B.2 Steps
GB/T 13346—2012/IS02082:2008 The surface area of ​​the small parts should not be less than 1cm2, and the number of parts taken should meet the requirement that the coating mass is not less than 100mg. Weigh the parts to the nearest milligram and remove the coating with a suitable stripping solution at room temperature. If the shape of the parts is complex, the purchaser shall specify the test and assessment area L (see 4.2b)]. Rinse the parts under self-watering water. If necessary, brush them to remove loose deposits on the surface of the parts, dry and weigh them: record the weight loss. Calculate using the following formula:
d+(Am - 10°)/(A -p)
Weight loss, expressed in milligrams;
-According to the measured surface area, expressed in square millimeters; p--density, expressed in grams per cubic centimeter. The density of the coating is usually 8.6g/ctn. 9Ammonium nitrate (NH4NO,), B.2 Steps
GB/T 13346—2012/IS02082:2008 The surface area of ​​the small parts should not be less than 1cm2, and the number of parts taken should meet the coating mass of not less than 100mg. Weigh the parts to the nearest milligram and remove the coating with a suitable stripping solution at room temperature. If the shape of the parts is complex, the test and evaluation area L (see 4.2b) should be specified by the purchaser. Rinse the parts under self-watering water. If necessary, brush them to remove loose deposits on the surface of the parts, dry and weigh them: record the weight loss. Calculate with the following formula:
d+(Am - 10°)/(A -p)
Weight loss, expressed in milligrams;
-According to the measured surface area, expressed in square millimeters; p--density, expressed in grams per cubic centimeter. The density of the coating is usually 8.6g/ctn. 9Ammonium nitrate (NH4NO,), B.2 Steps
GB/T 13346—2012/IS02082:2008 The surface area of ​​the small parts should not be less than 1cm2, and the number of parts taken should meet the coating mass of not less than 100mg. Weigh the parts to the nearest milligram and remove the coating with a suitable stripping solution at room temperature. If the shape of the parts is complex, the test and evaluation area L (see 4.2b) should be specified by the purchaser. Rinse the parts under self-watering water. If necessary, brush them to remove loose deposits on the surface of the parts, dry and weigh them: record the weight loss. Calculate with the following formula:
d+(Am - 10°)/(A -p)
Weight loss, expressed in milligrams;
-According to the measured surface area, expressed in square millimeters; p--density, expressed in grams per cubic centimeter. The density of the coating is usually 8.6g/ctn. 9
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.