Bearing with gradient distribution of retained austenite and method of manufacturing the same

Abstract

The application discloses a bearing with gradient residual austenite distribution and a preparation method thereof. First, austenitizing quenching is performed on a bearing workpiece to obtain an initial structure containing uniform residual austenite; then, carbon atoms are inhomogeneously enriched through pulse magnetic field induction to construct a cross-section differentiated martensite transformation temperature gradient; subsequently, a temperature window screening type cryogenic process is adopted to selectively transform the surface layer residual austenite into martensite, freeze the deep layer residual austenite, and form a continuous and smooth gradient transition zone through segmented temperature control; in combination with in-situ magnetic monitoring, closed-loop control of the process is realized, and finally, the finished product is obtained through tempering, shaping and surface finishing. The bearing prepared by the application has high hardness, high dimensional stability and high toughness of the core, the gradient transition is smooth without stress concentration, and the service life and reliability of the bearing under extreme working conditions can be significantly improved.

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