摘要:
A low Mn-low Cr ferritic heat resistant steel consisting essentially of, in weight %: 0.02-0.20% C, up to 0.7% Si, less than 0.1% Mn, up to 0.8% Ni, 0.8-3.5% Cr, 0.01-3.0% W, 0.1-0.5% V, 0.01-0.20% Nb, 0.001-0.05% Al, 0.0005-0.05% Mg, 0.0005-0.01% B, less than 0.05% N, up to 0.03% P, up to 0.015% S, 0.001-0.05% Ti and the balance Fe and incidental impurities, wherein the B content is defined so as to satisfy the following formula (14/11)B>N-N(V/51)/{(C/12)+(N/14)}-N(Nb/93)/{(C/12)+(N/14)}-N(Ti/48)/{C/12)+(N/14)}. The steel can further contain optionally 0.01-1.5% Mo, and/or one or more elements selected from the group consisting of 0.01-0.2% La, 0.01-0.2% Ce, 0.01-0.2% Y, 0.01-0.2% Ca, 0.01-0.2% Ta and 0.01-0.2% Zr. The steel can be used in place of the austenitic steels or high Cr ferritic steels, since it has remarkably improved toughness, workability and weldability, and excellent creep properties at elevated temperatures.
摘要:
A precipitation-hardening-type Ni-base alloy exhibiting improved resistance to stress corrosion cracking in a sour gas atmosphere containing elemental sulfur at high temperatures is disclosed. The alloy consists essentially of, by weight %;______________________________________ Cr: 12-25%, Mo: over 9.0 and up to 15%, Nb: 4.0-6.0%, Fe: 5.0-25%, Ni: 45-60%, C: 0.050% or less, Si: 0.50% or less, Mn: 1.0% or less, P: 0.025% or less, S: 0.0050% or less, N: 0.050% or less, Ti: 0.46-1.0%, Al: 0-2.0%. ______________________________________