Plasma Nitriding Behavior of DIN 1.2344 Hot Work Tool Steel

Abstract

In the present investigation the effect of time and temperature on plasma nitriding behavior of DIN 1.2344 (AISI H13) steel is studied. Pulsed plasma nitriding process with a gas mixture of N2 = 25% + H2 = 75% and duty cycle of 70% is applied to cylindrical samples of DIN 1.2344 hot worked tool steel. X-ray diffraction, surface roughness, microhardness and ball on disc wear tests are performed and the behavior of plasma nitrided samples are compared. Scanning electron microscopy and optical microscopy are used in order to observe the microstructure of samples after nitriding. XRD results showed that the compound layer consists of dual phase. Hardness near the surface dropped by rising the process temperature and it increased with longer process duration. The comparison of μ results showed that, frictional properties at longer duration and lower temperature is similar to higher temperature and shorter duration.