LOW C-LOW SI-CR-MO STEEL USED UNDER WET STEAM CONDITION

摘要

PURPOSE:To obtain the titled low C-low Si-Cr-Mo steel particularly superior in B, C resistance to wet steam, by adding trace V and Al in addition to respective prescribed quantities of C, Si, Mn, Cr, Mo, Al, V. CONSTITUTION:Low C-low Si-Cr-Mo steel is composed of, by weight 0.02-0.14% C, 0.45% Si, 0.30-0.80% Mn, 0.70-1.60% Cr, 0.40-0.70% Mo as basic component further 0.005-0.08% V and 0.005-0.08% Al and the balance Fe with inevitable impurity. Inevitable admixture impurities of the extent contained in usual steel making process can be permitted to the steel. Namely, since high temp. cracking susceptibility at weld zone is increased, S and P as admixture impurity both suppressed to =0.25% are favorable. In case the steel in the invention is used under wet steam condition it has all of E.C. resistance, weldability, strength, toughness, etc.