Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is prepared in accordance with the rules given in GB/T 1.1 — 2009.
This standard was proposed by China Iron and Steel Association.
This standard is under the jurisdiction of the Technical Committee on Steel of Standardization Committee of China (SAC/TC 183).
Hot stamping steel sheet and strip for automobile
1 Scope
This standard specifies the terms and definitions, classification and steel grade representation methods, order details, dimension, shape, technical requirements of weight, test methods, inspection rules, packaging, mark and product quality certificate for hot stamping steel sheet and strip for automobile.
This standard is applicable to the manufacture of automobile safety structural parts. The thickness of cold-rolled and hot-dip aluminum-silicon steel sheets and strips is 0.50 mm～3.00 mm, and the thickness of hot-rolled steel sheets and strips is 1.20 mm～12.0 mm (hereinafter referred to as "steel sheets and strips").
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222 Permissible tolerances for chemical composition of steel products
GB/T 223.5 Steel and iron — Determination of acid-soluble silicon and total silicon content — Reduced molybdosilicate spectrophotometric method
GB/T 223.9 Iron,steel and alloy — Determination of aluminum content — Chrome azurol S photometric method
GB/T 223.11 Iron steel and alloy — Determination of chromium content — Visual titration or potentiometric titration method
GB/T 223.17 Methods for chemical analysis of iron, steel and alloy — The diantipyrylmethane photometric method for the determination of titanium content
GB/T 223.23 Iron,steel and alloy — Determination of nickel content — The dimethylglyoxime spectrophotometric method
GB/T 223.26 Iron,steel and alloy — Determination of molybdenum content — The thiocyanate spectrophotometric method
GB/T 223.37 Methods for chemical analysis of iron, steel and alloy — The indophenol blue photometric method for the determination of nitrogen content after distillation separation
GB/T 223.40 Methods for chemical analysis of iron, steel and alloy; The anion-exchange separation-sulphochlorophenol S photometric method for the determination of niobium content
GB/T 223.59 Iron, steel and alloy — Determination of phosphorus content — Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy — The sodium(potassium)periodate photometric method for the determination of manganese content
GB/T 223.68 Methods for chemical analysis of iron, steel and alloy — The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content
GB/T 223.69 Iron, steel and alloy — Determination of carbon contents — Gas-volumetric method after combustion in the pipe furnace
GB/T 223.76 Methods for chemical analysis of iron, steel and alloy — The flame atomic absorption spectrometric method for the determination of vanadium content
GB/T 223.78 Methods for chemical analysis of iron, steel and alloy — Curcumin spectrophotometric method for the determination of boron content
GB/T 228.1-2010 Metallic materials--Tensile testing — Part 1: Method of test at room temperature
GB/T 230.1 Metallic materials — Rockwell hardness test — Part 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T)
GB/T 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 708 Dimension, shape, weight and tolerance for cold-rolled steel strip and sheet
GB/T 709 Dimension, shape, weight and tolerance for cold-rolled steel strip and sheet
GB/T 2523 Measuring method of surface roughness and peak count for cold-rolled metal sheet (strip)
GB/T 2975 Steel and steel products — Location and preparation of samples and test pieces for mechanical testing
GB/T 4336 Carbon and low-alloy steel — Determination of multi-element contents — Spark discharge atomic emission spectrometric method (routine method)
GB/T 4340.1 Metallic materials — Vickers hardness test — Part 1: Test method
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 17505 Steel and steel products — General technical delivery requirements
GB/T 20066 Steel and iron — Sampling and preparation of samples for the determination of chemical composition
GB/T 20123 Steel and iron — Determination of total carbon and sulfur content Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 20124 Steel and iron — Determination of nitrogen content — Thermal conductimetric method after fusion in a current of inert gas (routine method)
GB/T 20125 Low-alloy steel — Determination of multi-element contents — Inductively coupled plasma atomic emission spectrometric method
GB/T 20126 Unalloyed steel — Determination of low carbon content — Part 2: Infrared absorption method after combustion in an induction furnace (with preheating)
GB/T 25052 Continuously hot-dip coated steel sheet and strip — Tolerances on dimensions, shape and weight
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
hot stamping; HS
technique that heats the steel sheet above the austenitizing temperature, stamp the heated steel sheet in a die, and simultaneously finish forming and quenching
3.2
hot-dip aluminum-silicon alloy coating; AS
coating obtained from immersing the pretreated steel strip in molten aluminum-silicon liquid on the hot-dip aluminum-silicon production line. The molten aluminum-silicon liquid contains aluminum and 5% ~ 11% silicon.
4 Classification and steel grade representation methods
4.1 Classification
4.1.1 Refer to Table 1 for the classification of steel sheets and strips by surface quality and the corresponding relationship of delivery surface.
Table 1 Surface quality classification
Surface quality grade Code Delivery surface
Ordinary grade surface FA Hot-rolled surface
Superior grade surface FB Hot-rolled pickled surface, cold-rolled surface and hot-dip aluminum-silicon surface
High grade surface FC Cold-rolled surface, hot-dip aluminum-silicon surface
4.1.2 Refer to Table 2 for cold-rolled and hot-dip aluminum-silicon steel sheets and strips classification according to the surface structure.
Table 2 Surface structure classification
Surface structure Code
Pitted surface D
Smooth surface B
4.2 Steel grade representation methods
4.2.1 The steel grade of hot rolled steel sheet and strip consists of the initials "HR" of "Hot Rolled", the specified minimum yield strength value/minimum tensile strength value after hot stamping, and the initials "HS" of "Hot Stamping". E.g. HR950/1300HS.
4.2.2 The steel grade of cold-rolled steel sheet and strip consists of Cold Rolled initials CR, specified minimum yield strength value/minimum tensile strength value after Hot Stamping, and hot stamping initials HS. E.g. CR950/1300HS.
4.2.3 The steel grade of hot-dip aluminum-silicon steel sheet and strip consists of Cold Rolled initials CR, specified minimum yield strength value/minimum tensile strength value after Hot Stamping, hot stamping initials HS and aluminum-silicon coating mark AS. E.g. CR950/1300HS+AS.
5 Order contents
5.1 Contracts or orders based on this standard shall cover the following items:
a) product name (steel sheet or strip);
b) serial number of this standard;
c) steel grade;
d) specification, dimension and roughness accuracy;
e) weight of hot-dip aluminum-silicon coating;
f) surface quality class;
g) surface structure;
h) edge state;
i) surface treatment (pickling and oiling);
j) weight;
k) packing method;
l) others.
5.2 For hot-rolled steel sheets and strips, if not specified in the order contract, they shall be delivered according to the common dimensions and roughness accuracy, with the surface quality level of FA and trimming state, and the surface treatment of hot-rolled pickled steel sheets and strips shall be delivered in the oiling state and packed according to the packing methods provided by the supplier.
5.3 For cold-rolled steel sheets and strips, hot-dip aluminum-silicon steel sheets and strips, if not specified in the order contract, they shall be delivered according to the common dimensions and roughness accuracy, with the surface quality level of FB, pitted surface structure and trimming state, and the surface treatment shall be delivered in the oiling state and packed according to the packing method provided by the supplier.
6 Dimension, shape and weight
The dimensions, shapes, weights and allowable tolerances of hot-rolled steel sheets and strips shall comply with GB/T 709, those of cold-rolled steel sheets and strips shall comply with GB/T 708, and those of hot-dip aluminum-silicon steel sheets and strips shall comply with GB/T 25052.
7 Technical requirements
7.1 Steel grade and chemical composition
7.1.1 Steel grade and chemical composition (smelting analysis) shall meet the requirements in Table 3. If the purchaser has a special requirement for chemical composition, it shall be negotiated when ordering.
7.1.2 The allowable tolerances of the chemical composition of the finished steel sheet and strip shall comply with the requirements of GB/T 222 .
Foreword i
1 Scope
2 Normative References
3 Terms and definitions
4 Classification and steel grade representation methods
5 Order contents
6 Dimension, shape and weight
7 Technical requirements
8 Test methods
9 Inspection rules
Annex A (Informative) Reference values of mechanical properties of hot stamping parts
Annex B (Normative) Test method for coating weight of hot-dip aluminum-silicon steel sheet
Annex C (Informative) Comparison of similar steel grades in domestic and foreign standards
