TITLE:
Investigation of the Relation between Rolling Contact Fatigue Property and Microstructure on the Surface Layer of D2 Wheel Steel
AUTHORS:
Shuaishuai Wang, Xiujuan Zhao, Pengtao Liu, Jinzhi Pan, Chunhuan Chen, Ruiming Ren
KEYWORDS:
D2 Wheel Steel, Rolling Contact Fatigue Property, Microstructure Evolution of the Surface Layer, The Formation and Propagation of Contact Fatigue Cracks
JOURNAL NAME:
Materials Sciences and Applications,
Vol.10 No.8,
August
8,
2019
ABSTRACT: Through the rolling contact fatigue experiment under the condition of the lubricating oil, this article investigated the relation between contact fatigue property and microstructure on the surface layer of D2 wheel steel. The results showed that although the roughness of the original specimen induced by mechanical processing would diminish to some extent in the experiment, the 0.5 - 1.5 μm thick layer of ultrafine microstructure on the original mechanically-processed specimen surface would still become micro-cracks and small spalling pits due to spalling, and would further evolve into fatigue crack source. Additionally, even under the impact of the load that was not adequate to make the material reach fatigue limit, the ferrite in the microstructure underwent plastic deformation, which led the refinement of proeutectoid ferrite grains. During the experiment, the hardening and the refinement caused by plastic deformation consisted with the theory that dislocation gave rise to plastic deformation and grain refinement. The distribution laws of hardness and ferrite grain sizes measured could be explained by the distribution law of the shearing stress in the subsurface.