GB/T 9799-2011 Metallic and other inorganic coatings Treated zinc coatings on iron and steel GB/T9799-2011 Standard download decompression password: www.bzxz.net
This standard specifies the requirements for treated zinc coatings on iron and steel. The content of this standard includes the information required to be provided by the electroplating manufacturer and the requirements for heat treatment before and after electroplating. This standard does not apply to: ———Zinc coatings on unformed iron and steel sheets, strips and wires; ———Zinc coatings on tightly wound springs; ———Zinc coatings for non-protective decorative purposes. This standard does not specify the requirements for the surface state of the base metal before electroplating, but defects on the surface of the base metal will have an adverse effect on the appearance and film performance. The thickness of the electroplated layer on threaded parts can be limited by thread grade or assembly dimensional requirements.
This standard was drafted in accordance with the rules given in GB/T1.1-2009.
This standard replaces GB/T9799-1997 "Zinc Electroplated Layer on Metallic Coatings Steel".
Compared with GB/T9799-1997, the main technical changes of this standard are as follows:
———The name of the standard is changed to "Treatment of zinc electroplated coatings on metal and other inorganic coatings on steel";
———Introduction is added;
———Abbreviations and symbols are added (see 3.2 and 3.3);
———The identification of electroplated coatings is added (see Chapter 5); ———
Service conditions, service life and classification number are deleted (Chapter 6 of the 1997 edition);
———Neutral salt spray test requirements are added (see 6.5);
———Conversion coating and other auxiliary treatment requirements are added (see 6.3);
———The requirements for heat treatment are modified (see 6.6 and 6.7, Chapter 7 of the 1997 edition);
———The identification of chromate conversion coating and other auxiliary treatments is added (see Appendix A);
———Added additional information on corrosion resistance, rinsing and drying, bulk workpiece handling and dyeing of chromate conversion coatings (see Appendix C).
This standard uses the translation method equivalent to ISO2081:2008 "Metallic and other inorganic coatings - treated zinc electroplated coatings on steel". For
Chinese documents that have a consistent correspondence with the international documents referenced in this standard, see Appendix NA.
This standard has made the following editorial changes:
———Added informative Appendix NA "Chinese documents that have a consistent correspondence with the international documents referenced in this standard".
This standard was 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 drafting units of this standard are: Wuhan Institute of Material Protection, Ma'anshan Dingtai Rare Earth New Materials Co., Ltd., Wuhan Aobang Surface Technology Co., Ltd., Tongxiang Tiesheng Line Equipment Co., Ltd., Tongxiang Tongde Electric Power Accessories Co., Ltd., Nanjing Tianxing Surface Technology Co., Ltd., Hangzhou Tiantang Umbrella Group Co., Ltd., Wuhan Kangjie Technology Co., Ltd., Wuhan Material Protection Electroplating Technology Productivity Promotion Center.
The main drafters of this standard are: Zhang Dezhong, Mao Zuguo, Shi Zhimin, Liu Jilu, Lu Zhi, Shen Hongwei, Chu Qifeng, He Jie, Deng Rizhi, Li Weijiang, Li Xiaodong, Chen Ya, Chen Xun, Chen Xiaolei, Yu Hui. The
previous versions of the standards replaced by this standard are:
———GB/T9799—1997.
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, metallic and other inorganic coatings
—Vocabulary
ISO2177 Metallic coatings—Measurement of coating thickness—Coulometric method by anodic dissolution
ISO2178 Non-magnetic coatings on 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

ICS25.220.40
National Standard of the People's Republic of China
GB/T9799—2011/ISO2081:2008
Replaces GB/T9799—1997
Metallic and other inorganic coatings—Electroplated coatings of zinc with supplementary treatments on iron or steel（ISO2081:2008,IDT）
Issued on December 30, 2011
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 October 1, 2012
This standard was drafted in accordance with the rules given in GB/T1.1-2009. GB/T 9799-2011/ISO 2081:2008 This standard replaces GB/T 9799-1997 "Metallic coatings - Zinc electroplating on steel". Compared with GB/T9799--1997, the main technical changes of this standard are as follows: - The name of the standard is changed to "Zinc Electroplated Coatings on Metallic and Other Inorganic Coatings for Treatment on Steel"; an introduction is added;
abbreviations and symbols are added (see 3.2 and 3.3); the identification of electroplated coatings is added (see Chapter 5); - the conditions of use, service life and classification number (Chapter 6 of the 1997 edition) are deleted; the requirements for neutral salt spray test are added (see 6.5); the requirements for conversion coatings and other auxiliary treatments are added (see 6.3); - the requirements for heat treatment are modified (see 6.6 and 6.7, Chapter 7 of the 1997 edition); the identification of chromate conversion coatings and other auxiliary treatments is added (see Appendix A); - additional information on the corrosion resistance, rinsing and drying of chromate conversion coatings, handling of bulk workpieces and dyeing is added (see Appendix C). This standard uses the translation method equivalent to ISO2081:2008 "Zinc Electroplated Coatings on Metallic and Other Inorganic Coatings for Treatment on Steel". The Chinese documents that have a consistent correspondence with the international documents normatively referenced in this standard are shown in Appendix NA. This standard has been edited as follows:
Informative Appendix NA "Chinese documents that have a consistent correspondence with the international documents normatively referenced in this standard" has been added. 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). Drafting units of this standard: Wuhan Institute of Materials Protection, Ma'anshan Dingtai Rare Earth New Materials Co., Ltd., Wuhan Aobang Surface Technology Co., Ltd., Tongxiang Tiesheng Line Equipment Co., Ltd., Tongxiang Tongde Electric Power Accessories Co., Ltd., Nanjing Tianxing Surface Technology Co., Ltd., Hangzhou Tiantang Umbrella Group Co., Ltd., Wuhan Kangjie Technology Co., Ltd., Wuhan Material Protection Electroplating Technology Productivity Promotion Center. The main drafters of this standard: Zhang Dezhong, Mao Zuguo, Shi Zhimin, Liu Jilu, Lu Zhi, Shen Hongwei, Chu Qifeng, He Jie, Deng Rizhi, Li Weijiang, Li Xiaodong, Chen Ya, Chen Xun, Chen Xiaolei, Yu Hui. The previous versions of the standards replaced by this standard are: GB/T9799---1997.
GB/T9799-2011/ISO2081:2008
Zinc electroplating can be obtained by electroplating acid zinc chloride, alkaline cyanide-free zinc, and alkaline zinc cyanide solutions. This electroplating is used for the protection and decoration of steel. Bright zinc electroplating is widely used, and bright zinc electroplating processes are also widely used. The protective performance of zinc electroplating is related to the thickness of the coating and the type of service conditions where the workpiece is exposed. For example, the corrosion rate of zinc under industrial environment exposure is generally higher than that under rural environment exposure. Therefore, when specifying the minimum thickness of the electroplating layer, the type of service conditions should be considered. Chromate conversion treatment and other post-treatments are usually carried out after electroplating zinc, which can enhance the corrosion resistance of the zinc electroplating layer. The appearance and suitability of the zinc electroplating layer depend on the surface state of the base metal. Therefore, the stakeholders should reach an agreement on whether the surface processing state of the base metal is suitable for electroplating.
When the purchaser specifically requests, the zinc coating may be free of chromate conversion treatment or replaced by other conversion treatments. This standard gives codes for chromate conversion and all other auxiliary treatment types. Chemical conversion coatings that do not contain hexavalent chromium or are chromium-free and comply with this standard are commercially available. The appearance of the conversion coatings produced by these alternative processes may be different from that of hexavalent chromium conversion coatings. Except for phosphating coatings, all types of chromate conversion coatings and non-traditional conversion coatings or alternative coatings shall meet the corrosion resistance requirements of this standard.
Standard grades of metals and alloys can be found in references [6] to [10]. I
GB/T 9799—2011/ISO 2081:2008 Metallic and other inorganic coatings
Treatment of zinc coatings on steel
Note: This standard may be inconsistent with certain national health, safety and environmental regulations and requires the use of some substances and/or processes that may be hazardous to health if appropriate measures are not taken. This standard does not discuss any health hazards, safety or environmental matters and regulations that may be involved in the use of this standard. It is the responsibility of the manufacturer, purchaser and/or user of this standard to establish appropriate and applicable health, safety and environmental regulations and to take appropriate measures to comply with national, local and/or international regulations and regulations. Compliance with this standard does not imply exemption from legal obligations.
1 Scope
This standard specifies requirements for treated zinc electroplated coatings on steel. The content of this standard includes information to be provided by the purchaser to the electroplating manufacturer and requirements for heat treatment before and after electroplating. This standard does not apply to:
Zinc electroplated coatings on unformed steel sheets, strips and wires; . -Zinc electroplated coatings on close-wound springs;
Zinc electroplated coatings for non-protective decorative purposes. This standard does not specify requirements for the surface condition of the base metal before electroplating, but defects in the base metal surface may have an adverse effect on the appearance and properties of the coating.
The thickness of the electroplated coating on threaded parts may be limited by dimensional requirements such as thread grade or assembly. 2 Normative references
The following documents are indispensable for the application of this document. For any dated reference, only the dated version applies to this document. For any undated reference, the latest version (including all amendments) applies to this document. ISO1463Metallic and oxide coatings-Measurement of coating thickness--Microscopical methodISO2064Metallic and other inorganic coatings--Definitions and conventions concerning the measurement of thicknessISO2080Metallic and other inorganic coatings--Surface treatment,ISO 2177Metallic coatings—Measurement of coating thickness—Coulometric method by anodic dissolutionISO 2178Non-magnetic coatings on magnetic substrates—Measurement of coating thickness—Magnetic methodISO 2819Metallic coatings on metallic substrates—Electrodeposited and chemically deposited coatings—Review of methods available for testing adhesionISO 3497Metallic coatings—Measurement of coating thickness—X-ray spectrometric method ISO3543Metallic and non-metallic coatings--Measurement of thickness-Beta backscatter methodISO3613Metallic and other inorganic coatings-Chromate conversion coatings on zinc, cadmium, aluminium+zinc alloys and zinc-aluminium alloys--Test methodsISO3892Conversion coatings on metallic materials--Determination of coating mass per unit area-Gravimetric methodsISO4518Metallic coatings-Measurement of coating thicknessProfilometric method ISO4519 Electrodeposited metallic coatings and related finishes--Sampling procedures for inspection by attributes ISO9587 Metallic and other inorganic coatings--Pretreatment of iron or steel to reduce the risk of hydrogen embrittlement ISO9588 Metallic and other in-organic coatings--Post-coating treatments of iron or steel to reduce the risk of hydrogen embrittlement ISO10289 Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates--Rating of test specimens and manufactured articles subjected to corrosion ISO 10587 Metallic and other inorganic coatings-Test for residual embrittlement in both metallic-coated and uncoated externally-threaded articles and rods-Inclined wedge method ISO 15724 Metallic and other inorganic coatings--Electrochemical measurement of diffusible hydrogen in steels-Barnacle electrode method ASTM B117 Standard practice for operating salt spray (fog) apparatus 3 Terms, definitions, abbreviations and symbols 3.1 Terms and definitions The terms and definitions defined in ISO 2064 and ISO 2080 apply to this document. 3.2 Abbreviations
C—rainbow conversion coating;
D—opaque chromate conversion coating;
ER—heat treatment to reduce hydrogen embrittlement;
X non-metallic materials;
plastics that can be electroplated;
heat treatment to reduce stress;
organic sealant.
3.3 Symbols
Al—chemical symbol for aluminum;
Cu—chemical symbol for copper;
Fe—chemical symbol for iron;
Zn—chemical symbol for zinc.
4 Information that the purchaser should provide to the electroplating manufacturer 4.1 Necessary information
The following information should be provided in the contract or order agreement, or in writing on the engineering drawings: a) The standard number GB/T9799 and the coating identification of this standard (see Chapter 5); GB/T9799-2011/IS02081:2008
b) Specified main surfaces, for example, marked with drawings or samples with appropriate markings; the nature of the base metal, surface condition and type of finishing (when these factors may affect the applicability and/or appearance of the electroplating layer); c)
(see Chapter 1);
d) Insurmountable surface defects are allowed Location of defects (hanger marks) (see 6.1); Type of finish, e.g., bright, dark or other finish, preferably with approved finish samples; e) Type of chromate conversion coating and other auxiliary treatments (see 6.3 and Appendix A); When the purchaser has special requirements, the chromate conversion coating may be eliminated, and non-traditional conversion coatings and/or other auxiliary treatments (see Table A.2), or paint-like coatings may be applied on the chromate conversion coating; g) Requirements for thickness and bonding strength tests (see 6.2, 6.4 and Appendix B); h) Requirements for tensile strength of workpieces and heat treatment before and/or after electroplating (see 6.6 and 6.7); i) sampling methods, acceptance levels or other inspection requirements (when inspection methods other than those specified in ISO 4519 are used) (see Clause 7); j) requirements for accelerated corrosion testing (see 6.5) and rating (see 6.5.2). 4.2 Additional information
The following additional information shall be provided to the electroplating manufacturer: a) special requirements or limitations on pretreatment of the workpiece to be plated (see references); b) other requirements, such as areas for testing and rating of workpieces of special shapes. 5 Marking:
5.1 General
Marking may appear on engineering drawings, purchase orders, contracts or detailed product specifications. The marking shall clearly indicate, in the following order, the base material, stress reduction requirements, type and thickness of the base coating (when present), thickness of the zinc coating, post-plating heat treatment requirements, type of conversion coating and/or auxiliary treatments (see references). 5.2 Marking Specifications The marking shall include the following: a) The term “electroplating layer”; b) The standard number of this standard, i.e. GB/T9799; c) A hyphen; GB/T9799-2011/ISO2081:2008 The chemical symbol of the substrate Fe, followed by the standard grade of iron or steel; d) Slash (/); Heat treatment to reduce stress ( =SR) (if stress-reducing heat treatment is required), followed by a slash (/); the chemical symbol for zinc, Zn;
represents the minimum thickness of the zinc electroplating layer in micrometers, followed by a slash (/); the symbol for heat treatment to reduce hydrogen embrittlement (ER) (if heat treatment to reduce hydrogen embrittlement is required), followed by a slash (/); i)
ji) where appropriate, indicate the code for the chromate conversion coating, followed by a slash (/); k) where appropriate, indicate the code for other auxiliary treatments (see Appendix A). Slashes should be used in the identification to separate the data ranges for different process steps. Double separators or slashes indicate that a step in the process is either not required or is cancelled (see ISO 27830).
If other auxiliary treatments are performed on the chromate conversion coating, the identification of the zinc electroplated coating with a thickness of 25 μm should be: Fe/Zn25/X/Y
Where:
X represents one of the chromate conversion coating codes given in Table A.1; Y represents one of the other auxiliary treatment coating codes given in Table A.2. The standard grade of the special alloy should be marked after the chemical symbol of the base metal. For example, the UNS number of the special alloy, or the equivalent national or local number, should be marked in the symbol <>. For example: Fe(G43400> is a UNS grade of high-strength steel. 5.3 Identification of the base material
The base material should be represented by its chemical symbol. If it is an alloy, the main component should be indicated. For example: a) Fe represents iron or steel;
b) Zn represents zinc alloy;
Cu represents copper and copper alloys;
d) Al represents aluminum and aluminum alloys.
Plastic substrates that can be electroplated are marked with the letters PL, and non-metallic substrates are marked with the letters NM. 5.4 Marking of heat treatment requirements
Heat treatment requirements should be marked as follows: a) The letters SR indicate heat treatment to relieve stress before electroplating, and the letters ER indicate heat treatment to reduce hydrogen embrittlement sensitivity after electroplating; b) Indicate the minimum temperature in degrees Celsius (℃) in parentheses: c) The duration of the heat treatment is measured in hours (h). For example: SR(210)1 ​​means that the stress relief heat treatment is 1 hour at 210℃. 5.5 Examples
The following are marking examples.
Example 1: A 12μm thick zinc electroplated layer (Zn12) on iron or steel (Fe), the coating is subjected to rainbow color chemical conversion treatment (C), and its identification is: electroplated layer GB/T9799-Fe/Zn12/C
Color fee Example 2: A 25dn thick zinc electroplated layer (Zn25) on iron or steel (Fe); in order to reduce the hydrogen cell, the coating is heat treated at 190 ℃ for 8 h, marked as ER(190)8; the coating is treated with opaque chromate (D) and sealed with an organic sealant (T2), and is marked as: electroplated layer GB/T9799-Fe/Zn25/ER(190)8/D/T2 Example 3: Same as Example 2, but the workpiece is subjected to stress reduction heat treatment before plating, with a minimum duration of 3h at 200°C, and is marked as: electroplated layer GB/T9799-Fe/SR(200)3/Zn25/ER(190)8/D/T24
6 Requirements
6.1 Appearance
GB/T9799—2011/IS02081:2008
Although this standard does not specify the surface condition, finish or roughness of the substrate before plating, the appearance of the electroplated layer depends on the surface condition of the substrate (see surface preparation in the references). There shall be no obvious visible coating defects such as blisters, pores, roughness, cracks or local absence of coating on the main surface of the electroplated parts, except for unavoidable coating defects caused by defects in the base metal. Contact marks on the workpiece are unavoidable and their locations shall be agreed upon by the interested parties (see 4.1). The workpiece shall be clean and free from damage. The zinc coating shall be bright unless otherwise specified by the purchaser. If necessary, samples that can demonstrate the required coating appearance shall be provided or confirmed by the purchaser (see 4.1e).
6.2 Thickness
The coating thickness indicated in the marking shall be the minimum local thickness. Unless otherwise specified by the purchaser, the minimum local thickness shall be measured on the main surface where it can be contacted by a ball with a diameter of 20 mm (see 4.1 and 4.2). The methods specified in ISO1463, ISO2177, ISO2178, ISO3497, ISO3543 and ISO4518 are applicable to the measurement of the thickness of various zinc coatings on steel.
When the thickness measurement is controversial, the method specified in ISO2177 shall be used to measure the main surface area of ​​the coating when it is greater than or equal to 100mm2; when the main surface area of ​​the coating is less than 100mm2, the average thickness of the coating shall be measured according to the method specified in Appendix B. The minimum value of the average thickness of the coating can be regarded as the minimum local thickness of the coating. Before measuring the thickness using the method specified in ISO2177, a soft abrasive, such as aluminum oxide grinding paste, shall be used to remove the chromate conversion film or other conversion film. When the conversion film is thick, the measurement result is slightly lower. When the coating is rough or matte, the results measured by the microscope method (ISO1463) and the profilometer method (ISO4518) may be unreliable; when the magnetic method is measured, the thickness of the rough or matte coating is greater than that of the smooth coating on the coating with equal mass per unit area. Table 1 gives the thickness values ​​that meet the protection requirements under various conditions of use. 6.3 Conversion coatings and other auxiliary treatments
When specifically requested by the purchaser, the chromate conversion treatment may be omitted or replaced by other conversion treatments, such as trivalent chromium conversion or phosphate conversion (see 4.1). Annex A gives the codes for chromate conversion and all other auxiliary treatments. Chemical conversion coatings that do not contain hexavalent chromium (such as trivalent chromium) or are chromium-free are commercially available in accordance with this standard. All types of chromate conversion coatings and non-traditional conversion coatings or alternative coatings, except phosphating coatings, shall meet the corrosion resistance requirements of this standard. However, the appearance of the conversion coatings produced by these alternative processes may be different from that of hexavalent chromium conversion coatings. The requirements and products given in Tables 1, 2, Tables A.1, A.2 and C.1 have been used and accepted by producers, purchasers and users of the metal finishing industry worldwide for decades. 6.4 Bond strength of zinc coating and chromate conversion coating When tested by friction polishing as specified in ISO 2819, the zinc coating shall continue to adhere to the base metal. The chromate coating (hexavalent or other) shall be subjected to a bond strength test in accordance with ISO 3613. All tests, including accelerated corrosion tests, shall be carried out 24 h after the chromate conversion treatment. 6.5 Accelerated corrosion test
6.5.1 Neutral salt spray test
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According to the neutral salt spray test (NSS) specified in ASTM B117, after the test is continued for the time specified in Table 1 and Table 2, the test surface shall be free of red corrosion products (see Table 1) and white corrosion products (see Table 2) when observed with the naked eye or corrected vision. Slight discoloration shall not be a reason for rejection.
GB/T9799—2011/IS02081:2008
The partial coating identification in Table 1 and Table C.1 gives the minimum local thickness of the zinc electroplated coating after chromate treatment under various service conditions. To ensure corrosion resistance, the thickness requirement of the coating depends on the severity of the service conditions. For example, the coating designation Fe/Zn5 is only suitable for dry indoor environments. When the use conditions become more stringent, the thickness of the zinc electroplating layer should be increased to ensure the corrosion resistance of the coating and to make the coating meet the requirements of the use conditions (see Table.1).
When long service life is required, such as steel structures, a thicker zinc coating can be obtained by hot-dip galvanizing according to ISO1461 (see reference [1].
The duration and results of the artificial atmospheric corrosion test have little to do with the service life of the electroplated parts. Therefore, the test results obtained cannot be used as an intuitive reflection of the corrosion resistance of the workpiece under service conditions. Table 1 Neutral salt spray corrosion resistance of zinc + chromium conversion film at the beginning of base metal corrosion (red rust) Electroplating layer identification
(partial)
Fe/Zn5/A
Fe/Zn5/B
Fe/Zn5/F www.bzxz.net
Fe/Zn5/C
Fe/Zn5/D
Fe/Zn8/A
Fe/ Zn8/B
Fe/Zn8/F
Fe/Zn8/C
Fe/Zn8/D
Fe/Zn12/A
Fe/Zn12/F
Fe/Zn12/C
Fe/Zn12/D
Fe/Zn25/A
Fe/Zn25/F
Fe/Zn25/C
Fe/Zn25/D
Duration of neutral salt spray test /
Table 2 Corrosion resistance of chromate conversion film at the beginning of zinc electroplating corrosion (white rust) Neutral salt spray test time /
Chromate conversion film code "
Free registered member
. See Appendix A.||t t||6.5.2 Corrosion rating
GB/T9799—2011/ISO2081:2008
After the neutral salt spray test, the samples shall be rated in accordance with ISO10289. The acceptable grade shall be specified by the purchaser. 6.6 Heat treatment to reduce stress before electroplating
When specified by the purchaser, steel parts with a maximum tensile strength greater than or equal to 1000MPa and tensile stress generated during machining, grinding, forging or cold forming shall be subjected to stress reduction heat treatment before cleaning and metal deposition. The process and grade of heat treatment shall be carried out as specified by the purchaser, or the purchaser shall specify the appropriate process and grade in accordance with ISO9587. When heat treatment for stress relief before electroplating or for reducing hydrogen embrittlement after electroplating is specified (see 6.7), the time and temperature of the heat treatment process shall be as specified by the purchaser. The strength shall be marked in the label in accordance with the provisions of 5.3, 5.4 and 5.5. Steel parts with oxide scale or dirt shall be cleaned before electroplating. For high-strength steel (tensile strength greater than or equal to 1000MPa), chemical alkaline degreasing or anodic electrolytic degreasing or mechanical degreasing shall be used to avoid hydrogen embrittlement during the cleaning process (see references). 6.7 Heat treatment to reduce hydrogen embrittlement
Steel parts with a maximum tensile strength greater than or equal to 1000MPa and surface-reinforced workpieces shall be heat treated to reduce hydrogen embrittlement. The process and grade of heat treatment shall be carried out in accordance with ISO9588 or as specified by the purchaser. When heat treatment for stress relief before electroplating or heat treatment to reduce hydrogen embrittlement after electroplating is specified (see 6.6), the time and temperature of the heat treatment process shall be marked in the label in accordance with the provisions of 5.3, 5.4 and 5.5. Unless otherwise specified by the purchaser, the actual effect of heat treatment to reduce hydrogen embrittlement shall be measured as follows: residual hydrogen embrittlement test on threaded parts according to ISO10587; relative dissolved hydrogen concentration in steel shall be measured according to ISO15724. Heat treatment to reduce hydrogen embrittlement shall be carried out before chromate chemical conversion treatment. 7 Sampling
Randomly select the number of samples specified in ISO4519 from the inspection batch. Inspect the workpieces in the sample to determine whether they meet the requirements of this standard, and divide the inspection batch into qualified batches or unqualified batches according to the sampling procedure in ISO4519. If other types of sampling inspection procedures are used, samples shall be randomly selected and the workpieces in the sample shall be inspected to determine whether they meet the requirements of this standard. Free
GB/T9799-—2011/IS02081:2008 Appendix A
(Normative Appendix)
Marking of chromate conversion coatings and other auxiliary treatments A.1 Overview
Chromate conversion solutions are usually acidic and may contain hexavalent chromium or trivalent chromium, with other salts added to improve the appearance and hardness of the coating. The zinc electroplating layer can be treated with a suitable solution to obtain bright, bleached, iridescent, olive green and black coatings. White films can also be obtained by bleaching the iridescent film in an alkaline or phosphoric acid solution. Table C.1 gives a guide to suitable coatings. Table A.1 lists the approximate surface density (mass per unit area) of each type of chromate conversion coating measured in accordance with ISO3892. Table A.1 Types, appearance and surface density of chromate conversion coatings Type
Bright film
Bleached film
Rainbow film
Opaque film
Black film
Typical appearance
Transparent, transparent to light blue
White with slight rainbow
Yellowish rainbow
Olive green
Surface density of film layer
PA/(g/m2)
0.55 is marked in the identification. Unless otherwise specified by the purchaser, the actual effect of heat treatment to reduce hydrogen embrittlement shall be measured as follows: residual hydrogen embrittlement test on threaded parts according to ISO10587; relative dissolved hydrogen concentration in steel shall be measured according to ISO15724. Heat treatment to reduce hydrogen embrittlement shall be carried out before chromate chemical conversion treatment. 7 Sampling
Randomly select the number of samples specified in ISO4519 from the inspection batch. Inspect the workpieces in the sample to determine whether they meet the requirements of this standard, and divide the inspection batch into qualified batches or unqualified batches according to the sampling procedure in ISO4519. If other types of sampling inspection procedures are used, samples shall be randomly selected and the workpieces in the sample shall be inspected to determine whether they meet the requirements of this standard. Free
GB/T9799-—2011/IS02081:2008 Appendix A
(Normative Appendix)
Marking of chromate conversion coatings and other auxiliary treatments A.1 Overview
Chromate conversion solutions are usually acidic and may contain hexavalent chromium or trivalent chromium, with other salts added to improve the appearance and hardness of the coating. The zinc electroplating layer can be treated with a suitable solution to obtain bright, bleached, iridescent, olive green and black coatings. White films can also be obtained by bleaching the iridescent film in an alkaline or phosphoric acid solution. Table C.1 gives a guide to suitable coatings. Table A.1 lists the approximate surface density (mass per unit area) of each type of chromate conversion coating measured in accordance with ISO3892. Table A.1 Types, appearance and surface density of chromate conversion coatings Type
Bright film
Bleached film
Rainbow film
Opaque film
Black film
Typical appearance
Transparent, transparent to light blue
White with slight rainbow
Yellowish rainbow
Olive green
Surface density of film layer
PA/(g/m2)
0.55 is marked in the identification. Unless otherwise specified by the purchaser, the actual effect of heat treatment to reduce hydrogen embrittlement shall be measured as follows: residual hydrogen embrittlement test on threaded parts according to ISO10587; relative dissolved hydrogen concentration in steel shall be measured according to ISO15724. Heat treatment to reduce hydrogen embrittlement shall be carried out before chromate chemical conversion treatment. 7 Sampling
Randomly select the number of samples specified in ISO4519 from the inspection batch. Inspect the workpieces in the sample to determine whether they meet the requirements of this standard, and divide the inspection batch into qualified batches or unqualified batches according to the sampling procedure in ISO4519. If other types of sampling inspection procedures are used, samples shall be randomly selected and the workpieces in the sample shall be inspected to determine whether they meet the requirements of this standard. Free
GB/T9799-—2011/IS02081:2008 Appendix A
(Normative Appendix)
Marking of chromate conversion coatings and other auxiliary treatments A.1 Overview
Chromate conversion solutions are usually acidic and may contain hexavalent chromium or trivalent chromium, with other salts added to improve the appearance and hardness of the coating. The zinc electroplating layer can be treated with a suitable solution to obtain bright, bleached, iridescent, olive green and black coatings. White films can also be obtained by bleaching the iridescent film in an alkaline or phosphoric acid solution. Table C.1 gives a guide to suitable coatings. Table A.1 lists the approximate surface density (mass per unit area) of each type of chromate conversion coating measured in accordance with ISO3892. Table A.1 Types, appearance and surface density of chromate conversion coatings Type
Bright film
Bleached film
Rainbow film
Opaque film
Black film
Typical appearance
Transparent, transparent to light blue
White with slight rainbow
Yellowish rainbow
Olive green
Surface density of film layer
PA/(g/m2)
0.5
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