High-strength, heat-resistant, ferritic steels with excellent resistance to embrittlement caused by precipitation of intermetallic compounds.

摘要

PURPOSE: To develop a ferritic heat resistant steel with a Co-contg. martensitic single phase structure having high creep rupture strength by adding specified amounts of Cr, Mo, W, Co and the other elements to steel. ;CONSTITUTION: This is a high strength ferritic heat resistant steel having a compsn. contg., by weight, 0.01 to 0.30% C, 0.01 to 0.80% Si, 0.20 to 1.50% Mn, 8 to 13% Cr, 0.01 to 3.00% Mo, 0.10 to 5.00% W, 0.05 to 6.00% Co, 0.002 to 0.80% V, 0.002 to 0.50% Nb, 0.0020 to 0.20% N and specified small amounts of one or ≥ two kinds among Ca, Ba, Mg, La, Ce and Y in the shape of precipitates or solid solution, moreover contg. Ti, Zr and one or ≥ two kinds of Ni and Cu or furthermore contg. B, and the balance Fe, excellent in creep rupture strength under a high temp. and high pressure environment and moreover excellent in intermetallic compound precipitating embrittlement resistance.;COPYRIGHT: (C)1996,JPO