Hot workability of three grades of tool steel

摘要: Three tool steels, a cold-work air-hardening grade, hot-work die and high-speed type, were deformed by torsion in the range of 900 to 1100 °C at rates 0.1 5 s•1. In series continuous deformation tests flow stress ductility determined. The exponent was proportional strain rate temperature reciprocal Arrhenius relationship. general for given condition, activation energy, start dynamic recrystallization increased steels order listed above; however, grade is superior other two grades. Multistage carried out on each steel determine its softening behavior during intervals between passes. Each test under isothermal conditions with constant rate, pass strain, interval duration. Softening occurred both recovery amount increasing temperature, accumulated strain. first similar having extensive 1000 °C, whereas experienced considerably less softening.