The manufacturability, processability and is superior in strength at elevated temperature after the hot long haul aging the rustless steel null for the automobile exhaust air manifold

摘要

PURPOSE: To produce a stainless steel for an automobile exhaust manifold excellent in productivity, workability and high temp. strength by preparing a stainless steel having specified chemical components in which the contents of Nb, Ta and Zr are prescribed. ;CONSTITUTION: A stainless steel having a compsn. contg., by weight, ≤0.02% C, 0.4 to 1.0% Si, ≤1.0% Mn, ≤0.04% P, ≤0.03% S, ≤0.015% Al, 10 to 20% Cr, ≤0.02% N, ≤0.5% Nb, 0.02 to 1.5% Ta so as to satisfy ≤0.5% in total of Nb and Ta and 0.01 to 0.15% Zr, contg. C, N and Zr so as to satisfy the inequality Zr%/91≤C%/12+N%/14, and the balance iron with inevitable impurities is prepd. Thus, the stainless steel for an automobile exhaust manifold excellent in high temp. strength after high temp. long time aging and excellent in workability and productivity can be obtd.;COPYRIGHT: (C)1995,JPO