| 摘要 |
PURPOSE:To obtain a roll increased in the hardness on the dulled part and improved in wear resistance by incorporating Mo, V or the like which are metals having the b.p. higher than that of Cr into Ni-Cr contg. steel having a specified compsn. for a roll material. CONSTITUTION:The surface of a roll for cold rolling hardened by hardening and tempering is irradiated with a laser beam and is subjected to dullwork to obtain a laser-dulled roll for cold rolling. In this method, a roll constituted of, by weight, 0.8 to 1.3 C, 0.5 to 3.0% Si, 0.2 to 1.5% Mn, 0.3 to 1.0% Ni, 2.0 to 7.0% Cr, 2.0 to 10.0% Mo and 1.0 to 4.0% V, and the balance Fe is irradiated with a laser beam, and, the dulled part after the irradiation is subjected to hardening treatment by tempering. Furthermore, the steel can be added with <=5.0% W or <=5.0% W and <=9% Co. In this way, in the alloy steel contg. secondary hardening components such as Mo and V, the recovery of the hardness by tempering is remarkable, so that the objective roll can be obtd. |
