| 摘要 |
PROBLEM TO BE SOLVED: To obtain a steel sheet low in core loss by incorporating either or both of Bi and Pb into a steel slab, subjecting it to hot rolling for a specified time in such a manner that the finish rolling is executed at a specified draft, executing final cold rolling at a specified draft and subjecting it to final finish annealing in such a manner that the content of water of hydration in a separation agent for annealing is controlled to a specified ratio. SOLUTION: A steel slab contg., by weight, 0.005 to 0.120% C, 1.5 to 7.0% Si, 0.03 to 3.50% Mn and inhibitor forming components is incorporated with either or both of Bi and Pb by 0.0005 to 0.100% in total, is subjected to hot rolling for 50 to 260 sec in such a manner that the draft in the finish rolling is controlled to 88 to 98%, is subjected to final cold rolling at a draft of 80 to 95% and is subjected to final finish annealing in such a manner that the content of water of hydration in a separation agent for annealing is controlled to 0.03% to reduce the content of Bi and/or Pb present in the steel to the one of two-thirds. The mechanism in which Pb and Bi having the low m.p. and not enter into solid solution function as inhibitors is explicated. |
