Effect of plasma nitriding potential on tribological behaviour of AISI D2 cold-worked tool steel

摘要

The effect of the nitrogen potential on the micro-abrasive wear resistance of AISI D2 plasma nitrided tool steel was evaluated. Plasma nitriding experiments were conducted in a pulsed plasma reactor using different nitrogen potentials. The results indicate that a nitrided layer, with finely dispersed nitrides, can be formed when shorter nitriding times and higher nitrogen potentials were used. Although the thickness of this layer is small, its wear resistance is higher than that observed at longer nitriding times. Increasing the nitriding time resulted in the formation of thicker layers, albeit with grain boundary nitrides, which are deleterious to wear resistance. For untreated material, three-body abrasive wear rolling was the dominant mechanism, and for nitrided material, the mechanism transition was not clearly observed in spite of its better wear resistance.