PRODUCTION OF STEEL SHEET FOR HEAT EXCHANGER HAVING EXTREMELY GOOD WORKABILITY

摘要

PURPOSE:To produce a steel sheet for heat exchangers having excellent workability by cold rolling the hot rolled steel sheet contg. specific ratios of C, Si, Mn, P, S, N, Al, Cr, and Ti and subjecting the steel sheet to annealing, temper rolling and narrow-width slitting under specific conditions. CONSTITUTION:The hot rolled steel sheet contg., by weight, =0.005% C, =0.07% Si, =0.20% Mn, =0.015% P, =0.008% S, =0.0040% N, 0.01-0.10% Al, 0.5-2.0% Cr, and =0.05% Ti; =0.05% 48/12C+48/14N+48/32S and contg. others such as inevitable impurities is cold-rolled. After this steel sheet is annealed at the temp. above the recrystallization temp. and below the A3 transformation point, the steel sheet is temper-rolled at 0.2-2.0% draft. A slitter adjusted in clearance in such a manner that the ratio of the shearing face to the total sheet thickness of the slit end face attains =60% is used at the time of slitting the steel sheet to a narrow width. The steel sheet for heat exchangers which has the excellent workability of =50% elongation and the excellent high-temp. oxidation resistance is thereby obtd.