THE TRANSFORMATION OF BALL-BEARING STEEL

Abstract

The authors studied the continuous cooling and isothermal transformatlon of ball-bearing steel after austenitizing at 1050°C for 30min. The results were as follows. (1) The begin-ning curve of pearlite transformation during continuous cooling calculated by Pumphry-Jones method were found to be in reasonable agreement with those determined experimentally. (2) In the products of continuous cooling transformation, no primary cementite and bainite were found, when the C and Cr contents were richer, while some primary cementite and bainite were found, when the C and Cr contents were poorer.