This standard specifies the technical requirements and test methods for zinc electroplating on steel. This standard applies to zinc electroplating that prevents corrosion of steel under various conditions of use. This standard does not apply to zinc electroplating on unformed steel plates, strips and wires, zinc electroplating on steel closely wound springs, and zinc electroplating for non-protective decorative purposes. GB/T 9799-1997 Metallic Covering Zinc Electroplating on Steel GB/T9799-1997 Standard Download Decompression Password: www.bzxz.net
This standard specifies the technical requirements and test methods for zinc electroplating on steel. This standard applies to zinc electroplating that prevents corrosion of steel under various conditions of use. This standard does not apply to zinc electroplating on unformed steel plates, strips and wires, zinc electroplating on steel closely wound springs, and zinc electroplating for non-protective decorative purposes.

GB/T 9799--1997
This standard is a revision of GB9799-88 based on ISO2081:1986 Zinc Electroplating on Metallic Coatings Steel. It is equivalent to the international standard in terms of technical content and complies with the requirements of GB/T1.1-1993 in terms of writing rules. When revising this standard, more specific relevant standard provisions were quoted in Chapter 8 and Article 9.2 of GB9799-88, and 3 types of debonding solutions were added in 10.1.2.2.
This standard replaces the original GB9799-88 "Zinc Electroplating on Metallic Coatings Steel" from the date of its release and implementation.
This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Metallic and Non-metallic Coatings. The responsible drafting unit of this standard is Wuhan Institute of Materials Protection of the Ministry of Machinery Industry. Participating units of this standard: Guangdong Dongguan Jinhui Electroplating Factory. The main drafters of this standard are Xie Ruibing and Pan De'an. This standard was first published in 1988.
GB/T9799—1997
ISO Foreword
ISO (International Organization for Standardization) is a worldwide federation of national standards bodies (IS member bodies). The work of formulating international standards is generally carried out through ISU technical committees. If each member body is interested in a topic determined by a technical committee, it has the right to make a statement to the committee. Governmental and non-governmental international organizations associated with ISO may also participate in this work. The draft international standard adopted by the technical committee shall be sent to the member bodies for approval before being adopted as an international standard by the ISO Council. According to ISO procedures, the members who participate in the voting shall At least 75% of the member groups must approve it to pass. The international standard ISO2081 was developed by the ISO/TC107 Technical Committee for Metallic and Other Non-Organic Coverings. This second edition has made technical revisions to the first edition (I502081-1973) and is a revision of the first edition. Users should note that all international standards will be revised. Therefore, unless otherwise specified, the other international standards referenced in this international standard are their latest versions.
1 Scope
Five Standards of the People's Republic of China
Metallic Coverings
Zinc Electroplating on Steel
Metallic Coatings-Electroplated coating of zinc on steel
This standard specifies the technical requirements and test methods for zinc electroplating on steel. This standard is applicable to zinc electroplating for preventing corrosion of steel under various service conditions. GB/T.9799-1997
eq ISO 2081.1986
replaces GB 9799-8B
This standard does not apply to zinc electroplating on unformed steel plates, strips and wires, zinc electroplating on steel coiled springs and zinc electroplating for non-protective decorative purposes. 2 Referenced standards
The provisions contained in the following standards constitute the text of this standard through reference in this standard. At the time of publication of this standard, the indicated versions are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T4955—1997 Measurement of coating thickness of metal coatings Anodic dissolution coulometric method (neyISO2177:1985) GB4956--85 Measurement of thickness of non-magnetic coatings on magnetic metal substrates Magnetic method (e9VIS02178.1982) GB 5267-85
GB 646286
Electroplated coatings on threaded fasteners
Method for microscopic measurement of cross-sectional thickness of metal and oxide coatings (eqVIS01463.1982) GB/T9793-1997 Other inorganic coatings Thermal spraying of zinc, aluminum and their alloys (neqIS0.2063.1973) GB 9800--88
Chromate conversion coatings of electroplated zinc and electroplated coatings (ISO4520,1981) Method for measuring thickness of metal coatings Wheel seat dimensions (eqyIS0 4518:1980) GB 11378--89
GB 12334--90
GB 12609—90
Metallic and other inorganic coatings Definitions and general rules for thickness measurement (eqVIS02064:1980) Sampling inspection procedures for electrodeposited metallic coatings and related finishes by counting (eqVIS04519:1980) GB/T13912—92 Metallic coatings Technical requirements for hot-dip galvanized coatings on steel products (neqIS01461.1973) 3 Meaning
This standard adopts the following definitions.
3.1 Significant surface Some surfaces on a workpiece that are electroplated or to be electroplated, on which the coating is important to the appearance and (or) usability of the workpiece. 3.2 Local thickness Local thickness The arithmetic mean of the specified number of thickness measurements within the main surface. 3.3 Minimum local thickness Minimum value of the local thickness measured on the main surface of a workpiece. Also known as the minimum thickness. 4 Base metal and
This standard does not put forward any requirements for the surface state of the base metal before electrogalvanizing. However, the supplier and buyer should agree on the surface state of the base metal. State Technical Supervision Bureau approved on July 25, 1997, Implementation on February 1, 1998
GB/T 9799—1997
When the zinc bond layer fails to meet the requirements of satisfactory appearance and (or) performance due to the poor surface quality of the base metal, it cannot be considered that the electroplating production quality does not meet the requirements.
5 Information that the purchaser should provide to the electroplating manufacturer: a) National standard number GB/T 9799;
b) Grading number (see Chapter 6); it should be noted that the purchaser must provide the grading number. It is not enough to only require electroplating according to GB/T9799 without the grading number;
c) Indicate the main surfaces, such as marking with drawings or providing samples with appropriate markings; d) The nature of the base metal, surface state and surface roughness (see Chapter 4); e) Appearance requirements of the coating;
f) Heat treatment requirements before and after electroplating (see Chapter 7);
Type of chromate or other conversion film (see Chapter 9); h) Sampling and inspection requirements;
i) Any special requirements or restrictions on pre-treatment and electroplating process (see Chapter 7). 6 Use cases, service life and classification numbers
6.1 Influence of use conditions and service life
The thickness requirement of the zinc coating depends on the severity of the use conditions and the length of the service life. Fe/Zn5 grade (see 6.2) is generally only used in dry indoor environments. As the use environment becomes more severe and (or) the service life is required to be longer, the thickness of the zinc coating used must be increased accordingly
6.2 Classification numbers
The classification numbers are composed in the following order:
a) The symbol Fe, indicating the base metal steel or iron, followed by a slash, b) The symbol Zn, indicating the zinc electroplating layer,
c) A number, indicating the minimum local thickness of the zinc coating, in μm: d) When necessary, a symbol is used to indicate the presence, level and type of chromate conversion film (see GB9800). Example: Fe/Zn 25 c1A
This classification number indicates that the electroplated zinc layer on the steel substrate is at least 25um, in addition, -chromate conversion film;
-chromate conversion film grade, 1;
-chromate conversion film type, bright type. 6.3 Correspondence between zinc coating and service conditions and service life Table 1 lists the classification number of zinc coating and the minimum thickness of zinc coating after chromium salt treatment (see 9.2) and their correspondence with the service environment and service life. When there is a chromium salt conversion film, the symbol specified in GB9800 shall be marked behind it, and the specific description of other conversion films shall be given separately.
Table 1 Grade number, minimum local thickness, service conditions and service life of zinc electroplating on steel Service conditions or service life
With the increase of severity of the service environment and (or? The service life is extended, the minimum peripheral thickness should be increased accordingly
Grade number
Fe/Zm 5
Fe/Zn &
Fe/Zn12
Fe/Zn 25
Minimum local thickness μm
1 It is recommended that zinc coatings of grade Fe/Zn12 and Fe/Zn25 should have a chromate conversion coating (see GB9800). GB/T 9799—1997
2 In any specific service environment, the protective effect of the zinc coating is generally proportional to the mass (surface density) of the zinc coating per unit area, and is usually also proportional to the thickness of the zinc coating.Therefore, for some special purposes, a 40 μm thick zinc coating can be used. When a very long service life is required, such as on steel structures, a thicker zinc coating is required, usually hot-bonded zinc (see GB/T13912) or sprayed zinc (see GB/T9793>.
7 Heat treatment
7.1 Overview
Some base metals should be heat treated in accordance with the provisions of 7.3 and 7.4 to reduce the risk of hydrogen damage. In all cases, the heat treatment time should be calculated from the moment when each workpiece fully reaches the specified temperature. Steel workpieces with a maximum tensile strength rating greater than 1050 MP (equivalent to a hardness value of approximately 34 HRC, 40 HV or 325 HB) and surface annealed workpieces do not require heat treatment. Preparation before plating should avoid alkaline or acidic solutions. Cathodic treatment is performed in the heat treatment. Note that for steel workpieces with a tensile strength greater than 14150MPa (equivalent to a hardness of about 4GHRC, 440HV or 415HB), it is recommended to use an electrolytic solution of a quenching system such as oxidative acid salts or oxides with a relatively high cathodic current efficiency. 7.2 Classification of steels
7.2.1 Except for surface quenched workpieces (see 7.3.2 and 7.4.2), the heat treatment conditions should be selected based on the given maximum tensile strength value. Steels should be classified according to the maximum tensile strength values ​​given in Table 2. If only the minimum tensile strength value of the steel is given, the corresponding maximum tensile strength value can be determined from Table 2.
Table 2 Classification of steels and the corresponding relationship between their maximum tensile strength values ​​and minimum tensile strength values ​​Given minimum tensile strength value Rmin
Rm min1 000wwW.bzxz.Net
1 000≤R min≤1 400
1400≤Rmins1750
1750
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