Effects of Annealing on Carbides Size and Distribution and Cold Formability of 1.0C-1.5Cr Bearing Steel

摘要

In order to control the size and distribution of carbides and improve the cold formability of 1.0C-1.5Cr bearing steel, the effects of annealing parameters during isothermal spheroidization were studied. Mean diameter of carbides (D), interparticle spacing of carbides (s), number of carbides per area (n), and carbides particle size distribution were measured. The cold formability was evaluated through hardness and fracture strain. The results show that when austenitizing time increases from 0.5 to 7 hours or austenitizing temperature increases from 1033 K to 1153 K (760 A degrees C to 880 A degrees C), the values of D and s both increase, and the value of n decreases. With the increasing of second annealing time from 0.5 to 2 hours or the increasing of second annealing temperature from 953 K to 993 K (680 A degrees C to 720 A degrees C), the values of D and s tend to increase and the value of n decreases. According to the measured values of D, s, and n, two models describing their relationships were proposed. In addition, the hardness decreases with the increasing of D. The fracture strain changes slightly at first and then decreases significantly when the value of D exceeds 0.36 mu m. (C) The Minerals, Metals & Materials Society and ASM International 2015