المجلة الدولية للعلوم والتقنية

The aim of this study is to investigate the effect of deep cryogenic treatment (DCT) at -196ᵒC, 20 hrs. On wear behavior and hardness of AISI D2 and AISI P20. The heat treatment cycles were investigated by carrying out DCT between hardening and double tempering. The results obtained from the preliminary analysis showed that the wear rate for AISI P20 tool steel is higher than that of the wear rate of AISI D2 which led to better improvement in term of wear resistance of AISI D2 tool steel. The influence of DCT on hardness of tool steels were also investigated and the increase of hardness of AISI D2 was more obvious compared to AISI P20. A comparison of the two results reveals an improvement of hardness and wear resistance in deep cryogenic treatment DCT process of AISI D2 compared to AISI P20 for certain soaking time which was observed by micro-structural examination. In addition, it was more pronounced when it’s carried out immediately after hardening and before tempering where the transformation of retained austenite was high lighten by means of enhanced destabilization of martensite