Contact Failure analysis of Nitrided 32Cr2MoV Coated with TiN by Multi-Arc Ion Plating

摘要

In this paper, TiN coating was deposited onto the nitrided 32Cr2MoVA by multi arc ion plating and proceeded line contact fatigue experiment to investigate the influence of hard coatings on the contact failure properties of nitriding steel. The results of experiment show that pitting is primary type of contact fatigue failure for TiN coated 32Cr2Mo V and the pits on the TiN coated surface are shallower and smaller than that of the nitrided 32Cr2MoV. After TiN coating produce crisping and desquamation under higher contact fatigue loads, the exposed matrix surface begin to bear the contact load. The superficial microstructure of TiN coated 32Cr2MoV was more fine, and content of nitrides were higher than that of the nitrided, which insured the distribution of hardness gradient of subsurface was more rational than that of nitrided 32Cr2MoV. The contact fatigue strength of TiN coated 32Cr2MoV is greater about 200MPa than that of the nitrided 32Cr2MoV.