奥氏体不锈钢连杆裂纹分析  

Cracks Analysis of Connecting Rod of Austenitic Stainless Steel

作　　者：尚尔峰[1] 王志明[1] 

机构地区：[1]沈阳铸造研究所,沈阳110022

出　　处：《失效分析与预防》2016年第4期218-222,231,共6页Failure Analysis and Prevention

摘　　要：0Cr18Ni9奥氏体不锈钢高压隔离开关机构连杆在安装使用一年后产生裂纹。通过宏观形貌检验、低倍组织和显微组织分析、化学成分测定、能谱分析、晶间腐蚀倾向性试验、硬度检测等方法对裂纹产生原因进行分析。结果表明:连杆材料晶界弱化,裂纹以沿晶方式扩展。碳含量过高和热轧型材终轧温度偏低是导致材料晶界弱化、晶间腐蚀倾向性升高、塑性下降的主要影响因素;由硫含量超标引起的夹杂物增多是造成连杆塑性降低的次要影响因素。晶间腐蚀敏感性增强以及材料塑性偏低导致连杆在腐蚀工作环境中正常受力状态下产生裂纹。Cracks were found in the connecting rod of high voltage isolator ground switch made 0f 0Cr18Ni9 austenitic stainless steel after service for one year. The cause for cracks was analyzed by means of macro morphology examination,macrostructure and microstructure analysis,chemical analysis,energy spectrum analysis,detecting susceptibility to intergranular corrosion and hardness test. The results reveal that cracks propagated along grain boundary because of grain boundary weakening. Grain boundary weakening,high susceptibility to intergranular corrosion and decreasing of plasticity were primarily caused by higher carbon content and lower finish rolling temperature. Additionally,the poor plasticity of the connecting rod may also be due to large amounts of inclusions induced by high sulphur. As a result,high susceptibility to intergranular corrosion and poor plasticity caused cracks under working stress in corrosion environment.

关 键 词：奥氏体不锈钢 连杆 晶间腐蚀 裂纹 夹杂物 固溶处理 

分 类 号：TG142.71[一般工业技术—材料科学与工程]