| 摘要 |
PCT No. PCT/JP93/01314 Sec. 371 Date Jun. 29, 1994 Sec. 102(e) Date Jun. 29, 1994 PCT Filed Sep. 14, 1993 PCT Pub. No. WO94/06948 PCT Pub. Date Mar. 31, 1994.The present invention provides a non-aging at room temperature ferritic single-phase cold-rolled steel sheet or hot-dip galvanized steel sheet for deep drawing and having excellent fabrication embrittlement resistance and paint-bake hardenability, by heating a slab comprising, in terms of % by weight, 0.0001 to 0.0015% of C, not more than 1.2% of Si, 0.03 to 3.0% of Mn, 0.01 to 0.15% of P, 0.0010 to 0.020% of S, 0.005 to 0.1% of Al, 0.0001 to 0.0080% of N and 0.0001 to 0.0030% of B and optionally 0.1 to 3% of Cr with the balance consisting of Fe and unavoidable impurities, hot-rolling the heated slab at a finishing temperature of not lower than (Ar3-100) DEG C., cooling the hot-rolled coil within 1 sec after the hot rolling at a rate of not less than 50 DEG C./sec from the finishing temperature to a temperature in the range of from 600 DEG to 750 DEG C. and coiling the cooled strip in said temperature range, cold-rolling the coil with a reduction ratio of not lower than 60% and conducting continuous annealing or continuous hot-dip galvanizing in the temperature range of from 600 DEG to 900 DEG C.
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