HOT ROLLED STEEL PLATE EXTREMELY EXCELLENT IN BULGE FORMABILITY AND HAVING HIGH CORROSION RESISTANCE AND HIGH STRENGTH AND ITS PRODUCTION

摘要

PURPOSE: To produce a hot rolled steel plate extremely excellent in bulge formability, having high corrosion resistance and high strength, and reduced in costs. ;CONSTITUTION: This steel plate has a composition containing, by mass, 0.08-0.25% C, 0.7-2.5% Si, 0.8-2.5% Mn, 0.02-0.10% P, ≤0.005% S, 0.1-0.5% Cu, and 0.01-0.1% Al and further containing, if necessary, one or ≥2 kinds among 0.0001-0.0050% Ca, 0.01-0.3% Mo, and 0.01-0.3% Ni. Morever, C concentration in retained austenite is regulated to ≥0.7%. Further, in the hot rolling method of forming this structure, finishing temp., cooling conditions, and coiling temp. conditions are respectively specified.;COPYRIGHT: (C)1995,JPO