| 摘要 |
<p>PCT No. PCT/JP94/01752 Sec. 371 Date Jun. 14, 1995 Sec. 102(e) Date Jun. 14, 1995 PCT Filed Oct. 18, 1994 PCT Pub. No. WO95/11320 PCT Pub. Date Apr. 27, 1995This invention aims at obtaining a cold steel sheet having excellent cold formability irrespective of a high N content in order to re-utilize a scrap steel generated from scraps. A steel sheet comprising not greater than 0.1% of C, 60 to 150 ppm of N, not greater than 0.4% of Mn satisfying the relation Mn/S>/=7, not greater than 0.030% of S, not greater than 0.1% of Al and not greater than 0.08% of Ti satisfying the relation N (%)-Ti/3.42 (%)</=0.007, wherein the size of TiN in the weight at least +E,fra 1/2+EE of the total TiN weight is 0.05 to 10 mu m, is obtained. When production is made by continuous annealing, Ti is added so as to satisfy the relation N (%)-Ti/3.42 (%)</=0.004% and furthermore, high temperature winding is effected in hot rolling or B is added. When production is made by box annealing, the Ti content is adjusted so as to satisfy the relation 0.002%</=N (%)-Ti/3.42 (%)</=0.007%, a slab heating temperature is set to a higher temperature and the winding temperature of a hot rolled sheet is set to a lower temperature.</p> |
