EFFECT OF TEMPERATURE, TIME AND GAS COMPOSITION ON PLASMA NITRIDING OF DIN 1.2344 LOW ALLOY STEEL

In this study, DIN 1.2344 low alloy steel samples were plasma nitrided at 500℃,550℃ and 600℃ temperatures, 2, 4 and 6 h times in 75%N2-25%H2 and 25%N2- 85%H2 gas compositions. Diffusion zone was determined by optical microscopy. Phases formed in these layers were studied by X-ray diffraction method. Also,micro hardness changes from surface to core of the samples were determined. The results showed that phases of Fe3N, Fe2N and Cr2N have been created in all of specimens. Results have shown that depth of diffusion zone increases with temperature and time increase. In addition, hardness and hardness depth have increased by increasing time and temperature, but decreased by increasing nitrogenvolume percent. The thickness of compound layer has been affected by increasing temperature and time of plasma nitriding process. The results have designed and analyzed with DX7 (Design of experimental) software for determining optimum condition