FERRITIC STAINLESS STEEL HAVING EXCELLENT OXIDATION RESISTANCE, SECONDARY PROCESSING BRITTLENESS RESISTANCE AND WELD ZONE TOUGHNESS

• Main Authors: NISHIDA YUKIHIRO, FUJIMURA YOSHIYUKI, OKU MANABU
• Format: Patent
• Language: English
• Published: 29.09.2011
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a ferritic stainless steel which has excellent oxidation resistance, secondary processing brittleness resistance and weld zone toughness. SOLUTION: The ferritic stainless steel having excellent oxidation resistance, secondary processing brittleness resistance and weld zone toughness has a composition comprising, by mass, ≤0.03% C, ≤1.2% (preferably 0.3 to 1.2%) Si, ≤1.0% Mn, ≤0.04% P, ≤0.01% S, ≤2% Ni, 19 to 26% Cr, ≤0.03% N, 0.5 to 1.5% Al, ≤0.3% Ti and 0.0005 to <0.003% B, and, if required, comprising one or more kinds selected from ≤0.5% Nb, 0.05 to 0.5% Mo, 0.05 to 0.5% Cu, 0.05 to 0.5% V, 0.05 to 0.5% Zr, 0.001 to 0.05% REM (rare earth metals) and 0.001 to 0.01% Ca, and the balance Fe with inevitable impurities. and in which increased volume by oxidation after 1,000°C×800 h in a sheet thickness of 0.5 mm is ≤5 mg/cm2, transition temperature in a drop hammer test satisfies ≤-50°C, transition temperature in a Charpy impact test in a TIG toe weld zone in a sheet thickness of 1.5 mm satisfies <0°C, and also, inequality (1): 1.5≤Si%+2Al%+100(B%)≤3.0 is satisfied. COPYRIGHT: (C)2011,JPO&INPIT