... pipe etc. used for high pressure boiler working temperature between 450°C ~ 650 °C.Main steel grades:GB :10,20,20G,20MnG,25MnG ... ,15CrMoG,12Cr2MoG,12Cr1MoVG,12Cr2MoWVTiB,10Cr9Mo1VNbetc.ASTM: Grade A,C,D, Grade A-1,C,BS: 320 CFS, 440,243,620-460,622 ...