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5. Technical requirements
5.1 Trademark and chemical compositions
5.1.1Trademark of steel and chemical constitution (smelting ingredient) shall conform to requirements of Table 1. 5.1.1.1If the residual elements like chromium, nickel and copper in the steel can be guaranteed by the supplier, analyses may not be prceeded. 5.1.1.2As for steel smelted by oxygen converter, nitrogen content thereof shall be no greater than 0.008%, if the supplier can guarantee the quality, analyses may not be proceeded. 5.1.1.3As for 08 steel, aluminium is allowed to be used to replace silicon for deoxidation, at this point, lower limit of manganese content in the steel is 0.25%, silicon content is no greater than 0.03%, acid-soluble aluminium content in the steel is 0.015%~0.065% or aluminium content is 0.020%~0.070%. 5.1.2Permissible variation of chemical constitution of finished steel plates (sheets) and steel strips shall conform to requirements of GB/T 222. |