夹杂物尺寸及位置对51CrV4弹簧钢疲劳寿命的影响

Influences of Inclusion Size and Position on Fatigue Life of 51CrV4 Spring Steel

摘要: 用能谱仪、扫描电镜分析了51CrV4弹簧钢的疲劳断口, 研究了夹杂物尺寸及位置对该钢疲劳寿命的影响规律。结果表明: 51CrV4试验钢的疲劳强度为702.5 MPa, 在保证试样表面没有划痕和麻点的情况下, 疲劳裂纹主要起裂于椭球状且塑性较低的复杂氧化铝夹杂;在夹杂物尺寸越大和距离表面越近的情况下, 其疲劳寿命越低;在710 MPa应力水平下近表面夹杂物的临界尺寸为5.47 μm。

Abstract: The fatigue fracture was analyzed with EDS and SEM. Influences of inclusion size and position on the fatigue life of 51CrV4 spring steel were studied.The results show that the fatigue strength of the steel was 702.5 MPa. Fatigue cracks originated from ellipsoidal and low plasticity alumina inclusions without scratches and pittings on the surface. The larger the inclusion size and the closer the inclusion position from the surface, the shorter the fatigue life. The critical size of surface inclusions was estimated to be 5.47 μm when σ-1was 710 MPa.