Hot deformation behaviors of a 9Cr oxide dispersion-strengthened steel and its microstructure characterization

摘要

The hot deformation behaviors of a 9Cr oxide dispersion-strengthened (9Cr-ODS) steel fabricated by mechanical alloying and hot isostatic pressing (HIP) were investigated. Hot compression deformation experiments were conducted on a Gleeble 3500 simulator in a tem-perature range of 950–1100?C and strain rate range of 0.001–1 s?1. The constitutive equation that can accurately describe the relationship between the rheological stress and the strain rate of the 9Cr-ODS steel was established, and the deformation activation energy was calculated as 780.817 kJ/mol according to the data obtained. The processing maps of 9Cr-ODS in the strain range of 0.1–0.6 were also developed. The results show that the region with high power dissipation efficiency corresponds to a completely recrystallized structure. The optimal processing conditions were determined as a temperature range of 1000–1050?C with strain rate between 0.003 and 0.01 s?1.