中性腐蚀环境下钢丝的微动疲劳行为

在自制的微动疲劳试验机上开展中性腐蚀环境下单根钢丝的微动疲劳实验,考察在相同接触载荷下,不同振幅对钢丝的微动疲劳行为的影响,并用扫描电子显微镜观察疲劳钢丝的磨痕和断口形貌,研究钢丝微动疲劳断裂机制.结果表明:在较大的振幅下,钢丝的微动区均处于滑移状态,而在较小振幅下,钢丝的微动区从滑移状态逐渐转变为黏着状态;磨损机制主要为磨粒磨损、疲劳磨损、腐蚀磨损和塑性变形;钢丝疲劳寿命随着微动振幅的增大而减小;钢丝的疲劳断口可分为3个区域,即疲劳源区、裂纹扩展区及瞬间断裂区.

Fretting Fatigue Behaviors of Steel Wires under Neutral Corrosive Environment

Single steel wire freetting fatigue experiments were performed on a self-made fretting fatigue test machine under neutral corrosive environment.The effect of the different amplitude on the fretting fatigue behavior was examined under the same contact load.The morphologies of the fatigue steel wire grinding marks and fractures were observed on the scanning electron microscope.The results show that the fretting regime of steel wires runs in gross slip regime in larger amplitude,while it transforms from the gross slip regime into mixed fretting regime in smaller amplitude.Abrasive wear,fatigue wear,corrosion wear,and plastic deformation are the main fretting damage mechanisms in corrosive media.Fatigue life of steel wires is decreased with fretting amplitude increasing.Fatigue fracture surface can be divided into three regions,fatigue source region,crack extension area,and instantaneous fracture zone.