Dynamic Recrystallization Behavior of AISI 420 Stainless Steel under Hot Compression

摘要

Hot deformation behavior of AISI 420 stainless steel was studied under hot compression tests in the temperature range of 950 to 1150 ℃ and strain rates of 0.01 s~(-1) and 0.1 s~(-1). The study indicates that higher deformation temperature makes the peak stress pronounced and the occurrence of DRX is detected by inflection point in the work hardening rate vs. flow stress (θ-σ) plot, irrespective of the shape of flow stress curve. Local misorientation (M_L) was calculated to reveal the local change in the crystal orientation. The distribution of M_L suggested that the process of DRX reduces the local misorientation during hot deformation. The critical stress for initiation of DRX under different deformation conditions was determined by setting the derivative of the third order polynomial to θ-σ-plot. A good linear relationship between critical stress (σ_c) & critical strain (ε_c) and Zener-Hollomon parameter was established.