Cold rolled steel plate standards in various countries

Overview of cold-rolled steel plate standards (specifications, composition and properties) in various countries
At present, the main standards for cold-rolled steel plates of various stamping grades of ordinary strength are:
1) American ASTM A1008/ A1008M-2007 "Cold-rolled Steel Plate and Strip"
2) Germany DIN EN 10130-2006 "Cold rolled steel plate and strip"
3) Japan JIS G3141-2009 "Cold rolled steel plates and steel strips"
4) China GB/T 5213-2008 "Cold-rolled low carbon steel plates and steel strips" GB/T 5213-2008 "Cold-rolled low-carbon steel plates and steel strips" is mainly based on the production and use of domestic cold-rolled low-carbon steel plates and steel strips, and also refers to EN 10130-2006 "Cold-rolled low-carbon flat steel products for cold forming - ——Delivery Technical Conditions" (English version), the standard name of GB/T 5213-2001 "Cold-rolled thin steel plates and steel strips for deep drawing" has been revised and changed to "Cold-rolled low carbon steel plates and steel strips" , suitable for cold-rolled low-carbon steel plates and steel strips with a thickness of 0.30~3.5mm used in automobiles, home appliances and other industries. At the same time, a large number of modifications have been made to the main technical content, so that some indicators meet and exceed the requirements of foreign standards. The following are the main modifications: the grade naming method has been modified; the general and stamping steel grades DC01, DC03 and super deep drawing have been added. Steel grade DC07 is used; the surface quality level is modified from two to three; dimensions, shape, weight and allowable deviations directly adopt GB/T 708; the regulations on chemical composition are adjusted; SC1 is divided into F, Regulations on the three levels of HF and ZF as well as regulations on cupping, bending and metallography; requirements for surface roughness Ra are added to the surface structure; for products delivered in the state of steel strips, the length of the defective part of the surface is determined by 8% is adjusted to 6%. Referring to EN10130:2006, six stamping levels are set up: DC01, DC03, DC04, DC05, DC06, and DC07. Their yield strengths are no more than 280MPa, 240MPa, 210MPa, 180MPa, 170MPa, and 150MPa respectively. The corresponding tensile strength requirements are respectively 270~410MPa, 270~370MPa, 270~350MPa, 270~330MPa, 270~330MPa, 250~310MPa, the corresponding post-break elongation A80 values are required to be no less than 28%, 34%, 38%, 40%, 41% respectively. , 44%. Except for DC01, which has no limit, the r90 value is required to be no less than 1.3, 1.6, 1.9, 2.1, and 2.5 respectively. The n90 value is only specified for DC04, DC05, DC06, and DC07, and is required to be no less than 0.18, 0.20, 0.22, 0.23. It can be seen that GB/T 5213-2008 is in line with EN10130:2006, and the performance index requirements are basically the same. The elongation measurements are all A80 values, but in terms of composition, the upper limit of the mass fraction of Mn element in DC06 and DC07 is respectively The 0.25% and 0.20% specified in EN 10130:2006 were increased to 0.30% and 0.25%, and the requirements for aluminum content were increased. At the same time, the lower limit of yield strength of DC05 was adjusted from 140MPa to 120MPa. Compared with the American ASTM A1008/A1008M:2007, GB/T 5213-2008 adds two grades, DC06 and DC07, but lacks detailed regulations on the microalloying elements in the composition compared with ASTM A1008M:2007. ASTM A1008/A1008M:2007 It is divided into four levels: CS, DS, DDS, and EDDS. The corresponding yield strength ranges are 140~275MPa, 150~240MPa, 115~200MPa, and 105~170MPa. The corresponding elongation A50 values are not less than 30%, 36%, 38%, 40%. The upper and lower limits are specified for the r value and n value of DS, DDS and EDDS. The r value is 1.3~1.7, 1.4~1.8, 1.7~2.1 respectively, and the n value is 0.17~0.22 respectively. , 0.20~0.25, 0.23~0.27.

Compared with JISG3141:2009, GB/T 5213-2008 has added requirements for Alt and Ti in terms of composition. It corresponds to SPCC, SPCCT, SPCD, SPCE, SPCF, SPCG and adds DC07 level. The biggest difference in mechanical properties is that The post-break elongation of the plate thickness is adjusted from 28%~39%, 30%~41%, 32%~43%, 40%~45%, 42%~46% of the A50 value specified in JIS G3141:2009 to the A80 value is not less than 28%, 34%, 38%, 40%, 41%, DC07 is 44% (the samples corresponding to the standards are the 5# sample of JIS Z2201:1998 and the P6 sample of GB/T 228). The upper limit of yield strength decreases as the stamping level increases. The upper limit of each level in JIS G3141:2009 is required to be 190 ~ 240MPa, and the tensile strength is ≥ 270MPa.