Kyushu University, Fukuoka,
Sanyo Special Steel Co., Himeji,
Material Research Center, NSK Ltd., Fujisawa,
Pages: 19 Published: Jan 1998
This paper has two objectives. The first is to propose a new inclusion rating method based on statistics of extreme. The new inclusion rating method is applied to the evaluation of inclusions contained in two super clean bearing steels with a total oxygen level of 5ppm and 8ppm.
The second objective is to investigate the critical lower bound of inclusion size which influences the fatigue limit. For this purpose, a special steel with extremely low inclusion content, the electron beam remelted super clean bearing steel(EB-CHR), was prepared. It is shown that by decreasing the size of inclusions, the detrimental effect of inhomogeneities larger in size than inclusions, becomes more important. The small inhomogeneity is thought to be a local imperfectly heat- treated structure, bainite.
fatigue limit, bearing steel, inclusion, inhomogeneity, electron beam remelting, statistics of extreme
Paper ID: STP12122S