COLD-ROLLED STEEL SHEET HAVING EXCELLENT BENDABILITY AND HOLE EXPANDABILITY AND METHOD FOR MANUFACTURING SAME
卷宗概要
发明人
Chang-Hyo SEO; Yeon-Sang AHN
IPC 分类
CPC 分类
Provided is a method of manufacturing a cold-rolled steel sheet. The method includes: hot-rolling a steel slab under a finish rolling outlet temperature condition of Ar3 to Ar3+50° C. after reheating the steel slab; coiling the hot-rolled steel sheet at a temperature of 600° C. to 750° C.; by cold-rolling the hot-rolled steel sheet at a reduction rate of 40% to 70%; and overaging the cold-rolled steel sheet after continuous annealing, primary cooling at a cooling rate of 1 to 10° C./sec to 650° C. to 700° C., and secondary cooling at a cooling rate of 5 to 20° C./sec to a temperature of Ms−100° C. to Ms° C. The steel slab includes, by wt %, 0.03 to 0.07 of carbon, 2.0 to 3.0 of manganese, 0.01 to 0.10 of soluble aluminum, 0.3 to 1.2 of chromium, 0.03 to 0.08 of titanium, 0.01 to 0.05 of niobium, 0.0010 to 0.0050 of boron, 0.001 to 0.10 of phosphorous.
原文（中文）
Provided is a method of manufacturing a cold-rolled steel sheet. The method includes: hot-rolling a steel slab under a finish rolling outlet temperature condition of Ar3 to Ar3+50° C. after reheating the steel slab; coiling the hot-rolled steel sheet at a temperature of 600° C. to 750° C.; by cold-rolling the hot-rolled steel sheet at a reduction rate of 40% to 70%; and overaging the cold-rolled steel sheet after continuous annealing, primary cooling at a cooling rate of 1 to 10° C./sec to 650° C. to 700° C., and secondary cooling at a cooling rate of 5 to 20° C./sec to a temperature of Ms−100° C. to Ms° C. The steel slab includes, by wt %, 0.03 to 0.07 of carbon, 2.0 to 3.0 of manganese, 0.01 to 0.10 of soluble aluminum, 0.3 to 1.2 of chromium, 0.03 to 0.08 of titanium, 0.01 to 0.05 of niobium, 0.0010 to 0.0050 of boron, 0.001 to 0.10 of phosphorous.