Effects of Al on Microstructure and Mechanical Properties of Ultrahigh Carbon Steel (UHCS)

摘要

The effects of aluminum addition on the microstructure and mechanical properties of ultrahigh carbon steel (UHCS) after quenching and tempering were studied in this paper. The results showed that the addition of aluminum significantly enhanced the hardness and temperature resistance. The main reason was attributed to that the addition of aluminum inhibited the transformation of ε-carbide to cementite during tempering and thus resulted in the very high hardness during higher temperature tempering. And with increasing the aluminum content up to 6 %, the carbide network was completely disappeared because increasing addition of aluminum increased the eutectic carbon content significantly. This study not only demonstrated the effects of aluminum on the carbide network but revealed the extra high hardness of the ultrahigh carbon steel alloyed with aluminum, which provided a useful way to develop low density and high hardness bearing steel materials.