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冷轧辊接触疲劳剥落是在接触负荷下表层疲劳裂纹萌生扩展的断裂过程,与组织结构和内应力状态有关,是主要失效方式之一。本文研究淬火温度对86CrMoV7钢抗接触疲劳性能的影响。选择840、870、910和950℃四个淬火温度。测定了试样的接触疲劳寿命、硬度、残余应力和残余奥氏体量。并对金相组织、裂纹形貌及剥落断口进行了观察。研究发现,840℃淬火有最高的接触疲劳寿命;硬度和疲劳寿命有一定的对应关系,硬度为62～63HRC时接触疲劳寿命最高,更高的硬度反而使之下降。残余应力与疲劳寿命的关系较为复杂。金相组织对钢的接触疲劳寿命有重要作用:板条马氏体组织比片状马氏体组织抗接触疲劳性能好,适量的残余奥氏体可改善钢的抗接触疲劳性能。不同的裂纹及断口形貌对应不同的接触疲劳寿命。
Cold Roller Contact Fatigue Cracking is a fracture process of surface fatigue crack initiation and propagation under contact load, which is related to the structure of the structure and internal stress. It is one of the main failure modes. This paper studies the quenching temperature of 86CrMoV7 steel anti-contact fatigue properties. Select 840,870,910 and 950 ℃ four quenching temperature. The contact fatigue life, hardness, residual stress and retained austenite were measured. The microstructure, crack morphology and flaking fracture were observed. It is found that the highest contact fatigue life is obtained when quenched at 840 ℃. The hardness and fatigue life have a certain corresponding relationship. The contact fatigue life is the highest when the hardness is 62 ~ 63HRC, but the hardness is higher but the hardness is decreased. The relationship between residual stress and fatigue life is more complicated. The metallographic structure plays an important role in the contact fatigue life of steel: lath martensite is more resistant to contact fatigue than lamellar martensite, and the proper amount of retained austenite can improve the contact fatigue resistance of steel. Different cracks and fracture morphology correspond to different contact fatigue life.