The Effect of Flow Lines on the Mechanical Properties in Hot-Rolled Bearing Steel

Metals

Dongsheng Qian¹  Chengfei Ma¹  Feng Wang¹ 

[1] School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China;

关键词: hot rolling;    flow lines;    carbide;    anisotropy;    crack;    bearing steel;   

DOI  :  10.3390/met11030456

来源: DOAJ

【 摘 要 】

Hot rolling is an essential process for the shape-forming of bearing steel. It plays a significant role in the formation and distribution of flow lines. In this work, the effect of flow lines is investigated by analyzing the microstructure and mechanical anisotropy of hot-rolled bearing steel. It was found that carbides rich with Cr and Mn elements are distributed unevenly along the flow-line direction of the hot-rolled bearing steel. Moreover, the mechanical characterization indicates that ultimate tensile strength and yield strength do not have any significant difference in two directions. Nevertheless, an ultrahigh section shrinkage of 57.51% is obtained in the 0° sample that has parallel flow lines, while 90° sample shows poor section shrinkage. The uneven distributed carbides will affect the direction and speed of crack propagation during tensile deformation. Therefore, the 0° and 90° samples exhibit great difference in plastic property. Meanwhile, after tensile deformation, a delaminated texture is observed in the flow lines, which may be caused by different degrees of deformation of grains due to the uneven distribution of carbides. The results of this work may provide guidance for controlling and optimizing flow lines in the manufacturing of bearing rings.

【 授权许可】

Unknown