Development of Heat Resistant Long Life Through Hardening Bearing Steel (STJ2)

The development of a long life rolling element bearing for use under severe conditions is fundamental and important technology from an economic and environmental standpoint. Previously, NTJ2 was developed as a semi-heat resistant long life bearing steel, using silicon as an alloying element to enhance its heat resistance and life.

It is thought, though, that the demand for a bearing material that can withstand higher temperatures and have a longer life than NTJ2 will be needed in the future. Thus, a new heat resistant, long life material called STJ2 was developed optimizing the alloying elements in the silicon-alloyed bearing steel. The new steel has good dimensional stability to 250°C, long life and is very resistant to surface damage.