高锰钢在模拟海洋环境中的应力腐蚀行为

Stress corrosion behavior of high manganese steel in simulated marine environment

以低温高锰钢为研究对象,采用光学显微镜、扫描电镜、透射电镜、X射线能谱分析仪等设备对高锰钢进行微观观察,采用恒载荷应力腐蚀试验研究其在人工海水溶液中的应力腐蚀行为,采用电化学手段测试其腐蚀性能。结果表明:低温高锰钢晶粒度大小不一,显微组织主要为形变奥氏体,试样内存在位错及孪晶,晶界上未见明显析出物;在低温高锰钢的使用过程中,其缺陷部位优先发生腐蚀,在恒定应力条件下,材料表面局部生成微裂纹,且扩展速率较慢,材料对应力腐蚀不敏感;当应力发生变化时,试样中微裂纹与应力的平衡被打破,加速了裂纹的扩展和新微裂纹的萌生,材料在腐蚀环境下易发生应力腐蚀开裂。

Taking low temperature high manganese steel as the research object,the microstructure of high manganese steel was observed using optical microscope,scanning electron microscope,transmission electron microscope,and X-ray energy spectrometer.The stress corrosion behavior of high manganese steel in artificial seawater solution was studied by constant load stress corrosion test,and its corrosion performance was tested using electrochemical methods.The results show that the grain size of low temperature high manganese steel varies,and the microstructure was mainly deformed austenite.There were dislocations and twinning in the sample,and no obvious precipitates were found at the grain boundaries.During the use of low temperature high manganese steel,the defect areas preferentially underwent corrosion.Under constant stress conditions,microcracks were locally generated on the surface of the material,and the propagation rate was slow,making the material insensitive to stress corrosion.When stress changed,the balance between microcracks and stress in the specimen was disrupted,accelerating crack propagation and the initiation of new microcracks.Materials were prone to stress corrosion cracking in corrosive environments.