The Properties of Silicon Bearing Steel

Abstract

The effects of silicon content on the fatigue life and other properties have been investigated by using 0.5% carbon steels and SUJ 2 bearing steels (JIS) containing various amounts of silicon.
The results may be summarized as follows:
(1) The fatigue life of 0.5% carbon steel without undissolved carbide is increased by existence of about 1.5% silicon, that is, the fatigue life is much influenced by silicon in martensite. But the mechanical properties as hardness and compressive breaking strength are not influenced.
(2) The fatigue life of bearing steel with undissolved carbide in martensite is also much improved by existence of about 1.5% silicon.
(3) The toughness of bearing steel as quenched and tempered is increased by silicon, but the element is, not very much expected for the improvement of machinability and cold formability in annealed state.
(4) The fatigue life becomes longer as the silicon content in steel increases.
The reason is considered to be due to the increase of resistance to the softening by tempering.