Hot deformation behavior and processing maps of AISI 420 martensitic stainless steel

The hot deformation behavior of AISI 420 martensitic stainless steel is investigated though isothermal compression tests using a Gleeble-1500D thermal-mechanical simulator in a temperature range of 1123-1423 K and strain rate of 0.01-10 s−1. The hot deformation apparent activation energy is calculated about 363 kJ/mol. Processing maps are conducted on the basis of the experimental data and the dynamic materials model (DMM) to reveal the hot workability. When the strain is no less than 0.5, the optimum hot working condition corresponds to the deformation temperature range of 1280-1360 K and strain rate range of 0.01-0.05 s−1 with a peak power dissipation efficiency of about 0.43 at strain rate of 0.01s−1 and temperature of 1323 K. Two instability regions are detected from the processing maps and should be avoided during hot working.