METHOD OF PRODUCING HEAT-TREATED STEEL SHEET

To provide a method of producing a heat-treated steel sheet which can sufficiently suppress its deformation during a heat treatment.SOLUTION: The production method includes a cooling step of cooling a heated thick steel sheet S by passing it between a pair of upper and lower rolls 21, in a manner of sandwiched therebetween, in a cooling zone 22, and a shape correction step of correcting the shape of the thick steel plate S with a roller leveler 30 after the cooling step. In the cooling step, elongation strain at a plurality of positions in the plate width direction including at least a center part and an edge part of the plate width direction is determined. The thick steel sheet S is cooled at a passing speed V at which the difference in elongation strain between the maximum value and the minimum value of the elongation strain at each position of the plurality of positions is minimized.SELECTED DRAWING: Figure 3 【課題】熱処理時における鋼板の変形を十分に抑制することが可能な熱処理鋼板の製造方法を提供する。【解決手段】加熱された厚鋼板Ｓを上下複数対のロール２１で挟み込みながら通板させ、通過する冷却帯２２で冷却する冷却工程と、冷却工程後の厚鋼板Ｓの形状をローラレベラー３０によって矯正する形状矯正工程と、を含む熱処理鋼板の製造方法において、冷却工程では、少なくとも板幅方向センター部及び板幅方向エッジ部を含む板幅方向の複数位置における伸びひずみを求め、複数位置の各位置における伸びひずみの最大値と最小値との伸びひずみ差が最小となる通板速度Ｖで、厚鋼板Ｓを冷却する。【選択図】図３