NINE PERCENT CHROMIUM HEAT-RESISTING STEEL REDUCED IN SENSITIVITY TO LOW-AND HIGH-TEMPERATURE CRACKING, EXCELLENT IN TOUGHNESS, AND HAVING HIGH CREEP STRENGTH AT WELDED JOINT

摘要

PURPOSE:To reduce sensitivity to low- and high-temp. cracking, to improve toughness, etc., and to prevent material deterioration even after long use by incorporating prescribed percentage of C, Si, Mn, Cr, Mo, etc., and by limiting the amount of ferrite. CONSTITUTION:The titled heat-resisting steel consists of, by weight, 0.04-0.09% C, 0.01-0.5% Si, 0.25-1.5% Mn, 7-9.2% Cr, 0.5-1.5% Mo, 0.005-0.6% Sol. Al, 0.001-0.06% N (where C+N=0.13%), and the balance Fe, etc., in which the amount of ferrite (8F) is limited to =-5%. Above-mentioned amount of ferrite (8F) is represented by -104-555(C+6/7N)+32.9Si-49.5Mn+12.1Cr+39.1 Mo+46.1V+83.5Nb.