用扫描电镜、电子能谱及ICP光谱分析等方法,对断裂失效的Maraging(C)350马氏体时效钢扭杆零件进行了观察及测定。结合力学计算等方法,对扭杆的断裂进行了分析。结果表明,该零件在远低于强度极限的长期恒载下发生的断裂,其主要机理属于氢致脆性断裂,长期服役过程中产生的表面沿晶腐蚀是发生氢脆断裂的主要诱因。

Examinations and tests of some fractured maraging(c) 350 torsional rods were performed by means of SEM,electronic energy spectrum,ICP spectrum and so on. The result of causal analysis showed that the mechanism of the fracture which caused by the stress far below the ultimate strength was mainly related to the hydrogen embrittlement of the material,and intergranular corrosion,which had took place on the surface of the fractured rods during the long-term service process,was the inducement of the hydrogen embrittlement. The characteristic phenomena of the fracture were described.