JPS645611A - Composite roll and its production - Google Patents

Abstract

PURPOSE:To improve a shaft strength as well as a wear resistance and spall resistance by increasing the relative volume density ratio of the following thermal spray layer in the composite roll forming a thermal spray layer on the circumference of the shell part of a steel made core stock of high strength and high stiffness. CONSTITUTION:A composite roll blank is formed by providing a thick thermal spray layer 3 with the plasma thermal spray of the powder having a big deformation resistance on the circumference of the shell part 2 of the core stock 1 of the roll for rolling having high strength and high stiffness. This composite roll blank is then subjected to hot treatment by making the thermal spray layer 3 in the range of forging temp. after subjecting to a diffusion heat treatment, if necessary, for reinforcing the joining force of the core stock 1 and thermal spray layer 3 and heating it in the state of the temp. distribution 3 keeping down the temp. at the center of the core stock 1. With this hot treatment,the thermal spray layer 3 is preferentially forged more than the core stock 1 and even after machining the composite roll of good roughness is obtd.