Effect of hot deformation conditions and preliminary heat treatment on the properties of tungsten-molybdenum high-speed steels

Abstract

1. The initial rolling temperature (1000\2-1200\dg) and preliminary heat treatment have a large effect on the consistency of the properties of tungsten-molybdenum steels. An initial rolling temperature of 1000° ensures consistent properties of all 20 heats investigated after annealing and tempering. Initial rolling temperatures of 1100–1200° increase the susceptibility of tungsten-molybdenum steels to grain growth during quenching. Steels rolled at 1000–1200° and not subjected to preliminary softening heat treatment have a tendency to grain growth, unevenness of grain size, and brittleness of the fracture (with rolling at 1200°). 2. Initial rolling temperatures from 1000 to 1200\dg have no essential effect on the red hardness after tempering and annealing. Among the heats tested, the red hardness of 30% tended to decrease when the initial rolling temperature was raised to 1200\dg after tempering and after annealing.