| 摘要 |
At least both ends of a sheet bar in the length direction, which is obtained by roughly rolling a steel slab including 0.1 wt % or less of C, 0.5 wt % or less of Si, 1.0 wt % or less of Mn, 0.1 wt % or less of P, 0.05 wt % or less of S, 0.20 wt % or less of Al, and 0.015 wt % or less of N, are heated so that the temperature at both ends of the sheet bar in the length direction is 15° C. or more higher than the temperature of the remainder of the sheet bar. The rolling finish temperature is Ar3+20° C. to Ar3+100° C. in both end portions of the sheet bar in the length direction, and Ar3+10° C. to Ar3+60° C. in the remainder, and the rolling finish temperature in the both end portions in the length direction is 10° C. or more higher than that of the remainder, so that a steel strip after cold rolling and annealing has r values within ±0.3 of the average r value, and DELTAr within ±0.2 of the average DELTAr in the region of 95% or more of each of the total length and total width of the steel strip.
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