Skip to product information
1 of 6

PayPal, credit cards. Download editable-PDF and invoice in 1 second!

GB/T 19350-2012 English PDF (GBT19350-2012)

GB/T 19350-2012 English PDF (GBT19350-2012)

Regular price $130.00 USD
Regular price Sale price $130.00 USD
Sale Sold out
Shipping calculated at checkout.
Quotation: In 1-minute, 24-hr self-service. Click here GB/T 19350-2012 to get it for Purchase Approval, Bank TT...

GB/T 19350-2012: Metallic and other inorganic coatings -- Post-coating treatments of iron or steel to reduce the risk of hydrogen embrittlement

GB/T 19350-2012
Metallic and other inorganic coatings.Post-coating treatments of iron or steel to reduce the risk of hydrogen embrittlement ICS 25.220.40
A29
National Standards of People's Republic of China
Replacing GB/T 19350-2003
Metal and other inorganic coatings
To reduce the risk of hydrogen embrittlement after coating the treated steel (ISO 9588..2007, IDT)
2012-12-31 release
2013-10-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People 's Republic of China China National Standardization Management Committee released
Directory
Preface III
Introduction IV
1 range 1
2 normative reference document 1
3 Terms and definitions 1
4 Requirements 1
5 Elimination of brittleness treatment level 2
Heat treatment after processing 2
Appendix NA (informative appendix) and the normative reference in this standard international documents are consistent with the relationship between the Chinese document 5 Table 1 High-strength steel to eliminate brittle heat treatment level 3 Table 2 Some countries recommend the traditional treatment of high-strength steel to eliminate brittleness heat treatment level 3 Figure 1 treatment of the temperature of 190 ℃ ~ 220 ℃ heat treatment time - tensile strength curve 4 Preface
This standard is drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 19350-2003 "Metal and other inorganic coatings for the purpose of reducing the risk of hydrogen embrittlement. Reason ", compared with GB/T 19350-2003, the main technical changes are as follows. --- modified part of the introduction;
--- modified the scope of Chapter 1;
--- normative reference documents were re-adjusted;
--- amended the requirements of Chapter 4;
--- modified the first 6.1;
--- revised the note of paragraph 6.5;
--- modified Table 1, added Table 2;
--- modified Figure 1.
This standard uses the translation method equivalent to ISO 9588..2007 "metal and other inorganic coatings to reduce the risk of hydrogen embrittlement after coating Steel treatment ".
See Appendix NA for our documents in accordance with the normative correspondence between the normative references in this standard. This standard has made the following editorial changes.
--- with the national standard preface to replace the preamble of international standards; --- "this standard" instead of "this international standard";
- the addition of the data Appendix NA, and the normative reference in this standard international documents have a consistent correspondence between the Chinese documents. This standard is proposed by the China Machinery Industry Federation.
This standard is nationalized by the National Standardization Technical Committee on Metals and Nonmetallic Coatings (SAC/TC57). The drafting of this standard unit. Wuhan Institute of Materials Protection, Wuhan material warranty electroplating technology productivity promotion center. The main drafters of this standard. Yu Jing, Huang Yefong, Xu Yanfei, Pan ou, Jia Jianxin. This standard replaced the previous version of the standard release.
--- GB/T 19350-2003.
introduction
When the atoms of hydrogen into the steel and other metals, such as aluminum and titanium alloy, can cause its toughness or carrying capacity loss, or the occurrence of open (Usually sub-microscopic cracks), or when the applied stress is much lower than the yield strength of the alloy or even lower than the usual design strength of the alloy Disastrously brittle damage. This phenomenon often occurs in the use of conventional tensile test when the alloy toughness and no significant loss of the situation This phenomenon of alloy, usually referred to as hydrogen induced hysteresis, hydrogen induced cracking or hydrogen embrittlement. Cleaning, pickling, phosphating, electroplating, self-catalyzing process And corrosion or cathodic protection in the service of the material will cause hydrogen to penetrate the metal; in the cleaning, pickling, coating before the coating process, such as rolling Molding, machining and drilling, due to improper selection of lubricants caused by decomposition will lead to hydrogen into the metal; welding or brazing process can also So that hydrogen infiltration.
The heat treatment reduces the hydrogen embrittlement susceptibility caused by the tensile stress generated by the absorbed hydrogen atoms and/or the processing. Heat treatment time - temperature The degree of relationship depends on the composition of the steel, the structure and the coating type and coating method. For most high strength steels, the heat treatment effect With the reduction of processing time and the temperature drop sharply. This standard is intended to be used in the direction of electroplating, supply or processing of technical requirements, these requirements marked on the parts or purchase orders. Metal and other inorganic coatings
To reduce the risk of hydrogen embrittlement after coating the treated steel 1 Scope
This standard specifies a method for reducing the degree of hydrogen embrittlement susceptibility or sensitivity that may occur during surface finishes. The iron and steel heat treatment process specified in this standard can effectively reduce the hydrogen embrittlement susceptibility. These heat treatment processes are after finishing the surface, but at the time Any secondary conversion film before the process.
The stress relief heat treatment process used after the process but before the surface finish is specified in ISO 9587. This standard does not apply to fasteners.
Note. Heat treatment does not guarantee the complete elimination of the harmful effects of hydrogen embrittlement. 2 normative reference documents
The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article Pieces. For undated references, the latest edition (including all modifications) applies to this document. ISO 2080 Metal and other inorganic coatings Surface treatment, metals and other inorganic coatings Terminology (Metalicandother inorganiccoatings-Surfacetreatment, metalicandotherinorganiccoatings-Vocabulary) ISO 9587 metal and other inorganic coatings for the reduction of hydrogen embrittlement risk of steel pretreatment (Metalicandotherinorganic coatings-Pretreatmentofironorsteeltoreducetheriskofhydrogenembrittlement 3 terms and definitions
ISO 2080 and the following terms and definitions apply to this document. 3.1
Eliminate brittle heat treatment embrittlement-reliefheattreatment
In a certain temperature range and a certain processing time to achieve without changing the matrix metal metallurgy structure (such as recrystallization) and eliminate the parts have been brittle Sexual heat treatment.
4 requirements
The treated metal should be subjected to a heat treatment that reduces the risk of hydrogen embrittlement. In any case, the entire temperature of each part shall be of the specified temperature The heat treatment time is calculated.
Steel pieces and tables with actual tensile strength greater than or equal to 1000 MPa (corresponding hardness 300HV10, 303HB or 31HRC) Surface hardened parts should be heat treated unless their elimination of brittleness heat treatment is specified as ER-0. Should be avoided in containing alkali or acid The pretreatment of the cathodic processing step is performed. In addition, for a tensile strength higher than 1400MPa (the corresponding hardness of 425HV10,401HB Or 43HRC) steel parts recommended the use of high cathode efficiency of the plating solution. Table 1 and Table 2 lists the elimination of brittle heat treatment level, by the demand side according to Table 1 and Table 2 in the parts or purchase orders to the plating side, for Should be made by the parties or processing. If the parties do not require the elimination of brittleness treatment level, should be used ER-1 level. Note 1. The choice of treatment level is based on the experience or experimental data of the part or similar part and the particular alloy used. Due to alloy composition and structure, Dislocation distribution density, size, quality or design parameters and other factors, some parts without the elimination of brittle treatment can also get satisfactory performance, so the The parts intended to be heat-treated are designated ER-0.
Note 2. When the demand side does not specify the level, the use of processing time is one of the longest ER-1 level is a shortcoming. Electroplating side, supply side or processing side generally do not grasp The necessary information on the correct elimination of stress handling, such as design basis, stress caused by manufacturing operations, and so on. By the demand side of the parts designer, manufacturing engineer Or other qualified technical personnel in the parts or purchase orders on the provisions of the treatment level, in order to avoid unreasonable processing caused by the additional costs, is consistent Demand side interests.
Note 3. The use of corrosion inhibitors during pickling does not necessarily ensure that the hydrogen embrittlement is minimized. 5 Eliminate brittleness treatment level
5.1 In addition to the surface hardening parts, the heat treatment process should be selected according to the actual tensile strength. If only given the minimum tensile strength, or tensile If the strength is unknown, the heat treatment process should be selected based on the actual tensile strength converted from the known known or measured hardness values. Tensile Strength or by the known or measured by the hardness value of the corresponding value of the tensile strength should be provided by the demand side. For steel which has been completely or partially hardened, the corresponding classification should be made according to the hardness value of the surface hardened layer. 5.2 If the purchaser requires any test to verify the effectiveness of the brittleness treatment, the sampling and test methods used shall be specified. 6 after processing heat treatment
6.1 After the surface finish should be as soon as possible (not more than 3h) for heat treatment, preferably in the surface after finishing within 1h; the heat treatment should be in the table After finishing and before any grinding or other processing. For chromate-treated cadmium, tin, zinc and their alloy coatings or any of them His coating should be heat treated prior to chromate treatment; with the exception of zinc-cobalt alloy plating, it should be used to eliminate hydrogen embrittlement after passivation deal with.
Note 1. When the temperature exceeds 66 ° C, the chromate coating will be converted from a non-crystalline structure to a crystal structure and no longer have a "self-repair" characteristic. Although crystalline chromic acid The salt coating provides satisfactory corrosion protection in most natural environments, but it will no longer be able to pass the accelerated corrosion test. Note 2. The time referred to in this clause is the time between the end of the plating operation and the start of the heat treatment of the corresponding parts. 6.2 High strength steels are used to eliminate brittle heat treatment using the process conditions listed in Table 1, Table 2 and Figure 1. The actual tensile strength is below 1000MPa of steel, after plating without heat treatment.
6.3 for the presence of threaded or acute angle of the groove or thickness of more than 25mm parts, cadmium or galvanized immediately after the heat treatment and the most Less treatment 24h
6.4 For the actual tensile strength of more than 1800MPa of steel, the heat treatment of the shortest duration can be determined according to Figure 1, that type (1). t = 0.02Rm-12 (1)
Where.
t - the shortest duration, in hours (h);
Rm --- actual tensile strength in MPa (MPa).
6.5 For surface hardening (partial or total surface hardening) parts or bearing steels for electroplating, electroless plating or phosphating, as shown in Table 1, Table 2 and Figure 1 Processing, will result in unacceptable reduction in surface hardness; at this time should be selected at a lower temperature for heat treatment, but should not be less than 130 ℃, The shortest treatment time is 8h; this heat treatment is suitable for the actual tensile strength of less than 1400MPa steel parts. For cadmium, tin, zinc or its Alloy, the tensile strength of less than 1400 MPa, the shortest heat treatment time should be 16h; its tensile strength in the 1400MPa ~ 1800MPa in the range of 22h.
Note. Lower temperature treatment will adversely affect the fatigue strength of the part. 6.6 Heat treatment at 440 ℃ ~ 480 ℃ will reduce the hardness of chromium coating. If this temperature has an adverse effect on the performance of the steel, Such steel should not be treated with such a high temperature, but should be treated at a lower temperature of 190 ° C to 220 ° C. Tempered steel parts hot The treatment temperature should be below the tempering temperature of 50 ° C. Table 1 High-strength steel to eliminate brittleness heat treatment grade (see sections 4, 5 and 6 for details) Grade steel tensile strength Rm/MPa temperature/℃ minimum time (see Chapter 4)/h ER-0 does not require heat treatment (see Note 1 in Chapter 4)
ER-1 1701 ≦ R m ≦ 1800 190 to 220 22
ER-2 1601 ≤ Rm ≤ 1790 190 ~ 220 20
ER-3 1501 ≤ Rm ≤ 1600 190 ~ 220 18
ER-4 1401 ≤ Rm ≤ 1500 190 ~ 220 16
ER-5 1301 ≤ Rm ≤ 1400 190 ~ 220 14
ER-6 1201 ≤ Rm ≤ 1300 190 ~ 220 12
ER-8 1101 ≤ Rm ≤ 1200 190 ~ 220 10
ER-9 1000 ≤ Rm ≤ 1100 190 ~ 220 8
ER-13
Not shot peened parts and engineering chrome parts
1000? Rm?
440 ~ 480 1
ER-16
A hardened part of cadmium, tin, zinc or its alloys
Rm < 1400
130 to 180 16
ER-17
Part thickness> 25mm
And the presence of threaded or sharp groove parts
190 ~ 220 24
Table 2 Some countries recommend the traditional treatment of high-strength steel to eliminate brittleness heat treatment levels (see sections 4, 5 and 6 for details) Grade steel tensile strength Rm/MPa temperature/℃ minimum time (see Chapter 4)/h ER-0 does not require heat treatment (see Note 1 in Chapter 4)
ER-7 Rm ≥ 1525 177 ~ 205 12
ER-10 1250 ≦ Rm ≦ 1525 177 to 205 8
ER-11 1450 ≤ Rm ≤ 1800 190 ~ 220 6
ER-12 1000 ≦ Rm ≦ 1500 177 to 205 4
ER-14
Surface hardened parts
Rm < 1401
130 ~ 160 8
ER-15
A hardened part of cadmium, tin, zinc or its alloys
1401? Rm?
130 ~ 160 8
Description.
1 --- non-mandatory;
2 --- Mandatory;
X --- actual tensile strength (MPa);
Y - Minimum duration (h).
Figure 1 treatment of the temperature of 190 ℃ ~ 220 ℃ heat treatment time - tensile strength curve Appendix NA
(Informative)
And the normative reference in this standard international documents have a consistent correspondence between the Chinese documents Terminology for metal plating and chemical treatment and related processes (ISO 2080. 1981, NEQ) GB/T 3138-1995 GB/T 19349-2012 Metal and other inorganic coatings for steel pretreatment to reduce the risk of hydrogen embrittlement (ISO 9587..2007, IDT)

View full details