采用激光扫描共焦显微镜观察了成分与302不锈钢基本相同的冷拉拔0.3 mm不锈钢丝的表面形貌特征,并用扫描电镜对其显微组织进行了观察,对用此钢丝制备的金属橡胶隔振构件进行了疲劳试验并对钢丝疲劳断裂的原因进行了分析.结果表明:该不锈钢丝表面存在较多微米量级的凹凸体,其表面粗糙度Ra为3.447 μm;钢丝内部存在以硬质颗粒为核心,长轴方向与拉拔方向一致的梭形微孔洞;钢丝的疲劳裂纹均起源于表面,并且呈现多源特征,断口上的裂纹扩展区和瞬断区面积所占比例各半,裂纹扩展区有典型的舌形叠加波浪状疲劳辉纹,其形成与钢丝内部的梭形微孔洞有重要关系.

Using laser scanning confocal microscope (LSCM),the surface contour of  0.3 mm cold-drawn stainless steel wires with the composition close to 302 austenitic stainless steel was studied and the microstructure was observed by SEM. Fatigue test was performed on hollow cylinder-shaped metal rubber damper made of such wires,and the fatigue fracture reason of the wires was analyzed. The results show that there were a lot of concavo and convex micro bodies on the surface of the steel and the wires surface roughness Ra was 3.447 μm. There were shuttle-shaped micro holes along the drawing axis with hard particles as core in the microstructure of the steel. The cracks originated from the surface of the wires and each fracture had more than one crack origins. Steady and fast spreading area both took up 50% of the toal fracture. Waviness fatigue striation was piled with tongue-shaped wrinkles which had important relationship with the shuttle-shaped micro holes.