| 摘要 |
PURPOSE:To obtain a titled work roll having a specific quench-hardening curve and excellent in resistance to accident, by controlling a sub-zero treating temperature to control the amount of residual austenite in the structure after quenching. CONSTITUTION:In case of heat treating a work roll of forged steel, etc. used for a cold rolling mill, the roll is quenched by low-frequency induction heating, and the sub-zero treating temperature thereafter is controlled to control the amount of residual austenite in the structure after quenching. By this control, a roll having a quench hardening curve, wherein the roll surface has a >=94 Shore hardness, the decrease of hardness from the surface to the 10mm depth is >=3, the decrease of hardness from 10mm to 30mm is <=1 and the hardness at 30mm depth is >=90, is obtained. The roll has a deep hardened depth and high toughness. |
