Isothermal phase diagram of residual austenite in tempering

Abstract

1. The temperature-time conditions of intermediate high tempering after quenching at the carburization temperature can be substantiated on the basis of the results of investigations of the decomposition of residual austenite during the tempering process. For that isothermal diagrams of tempering have to be constructed. 2. The isothermal diagram of tempering of the model steel 95KhGNMFL shows that the intermediate high tempering of steel 18KhGNMFL is inexpedient. 3. The decomposition of residual austenite of the model steel 95KhGNMFL is accompanied by stabilization of the process, the same as is found with supercooled austenite. The temperature-time parameters of the stabilization of residual austenite are smaller than of supercooled austenite. 4. The thermokinetic diagram of tempering can be plotted according to the results of the investigation of the phase transformations during tempering with different heating rates.