INFLUENCE OF THE THERMAL CYCLIC TREATMENT ON THE PHASE COMPOSITION OF ION-NITRIDED SURFACE LAYERS OF 12Kh18N10T STEEL

摘要

We investigate phase transformations in ion-nitrided surface layers of 12Kh18N10T steel subjected to thermal cyclic treatment (heating up to 1050 K follows by cooling at a rate of 30 K/min) by the method of magnetic analysis with the help of a vibrating-coil magnetometer, which enables us to affect the quasistable quantitative martensite-to-austenite ratio in the nitrided surface layer of steel. It is shown that, as a result of the thermal cyclic treatment, the temperature of the direct martensitic transformation in the nitrided surface layer increases from 380 K in the first cooling cycle up to 540 K in the fifth cooling cycle.