... ,ASTM,JIS,BV,DNV Representative Grades of Steel Plates:Boiler and Pressure Vessel Steel Plate: 1>. Standard: ASTM / ASME Grade ... NR400ZL7>. GB 16Mn, 15MnV, 15MnVN, Q460CShipbuilding and Offshore Platform Steel Plate: Classification Society Certificate: CCS,DNV,GL,LR ... X56 (L390), X60 (L420), X65, X70Quenching and Tempering High Tensile Steel Plate: Standard: Special ConditionGrade: WH70Q, WQ590D, Q550D ...