The development of high speed steel rolls by extrusion casting

Abstract

Extrusion casting processes are developed for HSS rolls and the effects of the extrusion casting process on the properties of HSS rolls are investigated. It was found that pressure, pressing time and pressing speed are three important factors affecting the shrinkage cavity. At a pouring temperature of 1400–1450°C, a pressure of 150–160 MPa, a pressing time of 120–150 s and a pressing speed of 14–16 mm s^-1, compact structure HSS rolls were obtained, which had no segregation and a small working allowance. HSS rolls, which are used in high speed wire rod rolling mills, have a service life five to eight times greater than that of high Ni–Cr rapidly chilled cast iron rolls, and with their use the quality of rolled steel products has been improved.