Mechanical Properties and Microstructure Evaluation of Differently Cryogenically Treated AISI-H11 Steel

Mechanical properties and microstructure evolution of differently cryogenically treated AISI-H11steel has been evaluated in this study. Parameters chosen for cryogenic treatment cycles are soaking temperature (− 154 °C and − 184 °C) and soaking duration (6, 21, and 36 h). Mechanical properties obtained have been characterized to comprehend the influence of cryogenic treatment parameters vis-à-vis vacuum heat treatment and tempering on the hardness, toughness and tensile strength. The samples cryogenically treated at − 184 °C for a soak duration of 6 h and tempered at 600 °C for 2 h showed higher hardness, samples cryogenically treated at − 184 °C for a soak duration of 36 h and tempered at 600 °C for 2 h showed higher toughness and showed 12.8% reduction in tensile strength in comparison to conventionally treated samples. X-ray diffraction analysis showed that retained austenite contents of samples treated with various cryogenic treatments reduces to near zero.