Nsk Corporation

Hiroaki Sugiyama

Kiyoshi Hirakawa

Akitoshi Maeda

Manabu Ohhori

In a corrective tempering method and apparatus for a rolling element in which the thermal deformation of the rolling element is corrected within an extremely short time by utilizing plasticity exhibited during a metallic structure transforming process brought about by low-temperature tempering of the rolling element made of steel, the hardened rolling element is heated and pressured to a maximum temperature within a range of from 250 to 500&deg; C. by a heating device while set in correcting molds to correct the deformation of the rolling element at a degree of working within a range not exceeding an elastic deformation range of the rolling element at a room temperature. The rolling element can be heated also by an induction heating device in addition to a conduction heating device. A product whose inner/outer diameter correcting degree of deformation is 60% or more, dimension standardizing rate is 30% or more, surface roughness is less than Ra 0.2 &mgr;m, and surface hardness is HRC,or more can be obtained for a correction time within 6 minutes and an induction heating time within 30 seconds.

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Kanagawa, Japan

Hiroaki Sugiyama