Regular Article

The effects of temperature and strain rate on the hot deformation behavior of AISI H10 tool steel

Facuty of Material and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran

^* e-mail: m_morakabati@mut.ac.ir

Received: 26 June 2020
Accepted: 3 November 2020

Abstract

The hot deformation behavior of a H10 hot work tool steel was studied by performing hot compression tests over the temperature range of 900 to 1200 °C and strain rates of 0.001–1 s⁻¹ and total strain of 0.7. At temperatures below 1100 °C, the grain size is fine and below 20 μm. In this temperature range, grain size increase with temperature due to dissolution of carbides. Then by increasing temperature to 1150 and 1200 °C, the grain size is increased significantly due to growth of grains. The study on the effect of strain rate showed that at constant temperature of 1000 °C, the grain size increased from 4.8 to 6 μm with increasing strain rate from 0.001 to 1 s⁻¹. Also, this increase in the strain rate at temperature of 1100 °C lead to increase the grain size from 5.9 to 17 μm, due to the occurrence of dynamic recrystallization. At 1200 °C growth of grains causes to decrease grain size from 112 to 87 μm by increasing strain rate. According to the microstructural investigations, at the temperatures of 1000 and 1100 °C and strain rates of 0.01 and 0.1 s⁻¹ dynamic recrystallization was the main softening mechanism. As a result, the most suitable range for hot deformation was obtained at the temperature range of 1000–1100 °C and strain rates of 0.01–0.1 s⁻¹.