摘要
采用草酸电解浸蚀试验和恒电位极化试验研究了敏化处理前后304不锈钢脉冲电流止裂处的晶间腐蚀性能,得到适合评价裂纹止裂处晶间腐蚀性能的方法。结果表明:经脉冲电流止裂后,止裂处的凝固区、细晶区、形变马氏体区晶界处均未析出碳化物,而经恒电位极化后,晶界处的钝化膜完整,未发生晶间腐蚀;经草酸电解后,敏化试样止裂处不同区域的晶界处均发生了腐蚀,说明草酸电解法不能区分脉冲止裂后不同微区晶间腐蚀性能的差异;经恒电位极化后,敏化试样止裂处凝固区和细晶区晶界处的钝化膜稳定性较好,具有一定的耐晶间腐蚀能力,形变马氏体区发生了严重的晶间腐蚀;恒电位极化法是评价奥氏体不锈钢脉冲电流止裂处晶间腐蚀性能的一种有效方法。
The intergranular corrosion performance at pulse current crack arresting area of 304 stainless steel before and after sensitization was studied by oxalic acid electrolytic etching test and potentiostatic polarization test,and a method suitable for evaluating the intergranular corrosion performance at crack arresting area was determined.The results show that there was no carbide precipitated at grain boundaries in the solidification zone,fine-grained zone and deformed martensite zone at crack arresting area;after potentiostatic polarization,the passive film at grain boundaries was intact,indicating intergranular corrosion didn′t occur at the crack arresting area.The corrosion occurred at grain boundaries of different areas at crack arresting area of the sensitized specimen,indicating that the oxalic acid electrolysis method failed to distinguish the difference in intergranular corrosion performance among different micro-zones after pulse crack arrest.After potentiostatic polarization test,the passivation films at grain boundaries in the solidification zone and fine-grained zone at crack arresting area of the sensitized specimen had better stability and a certain ability to resist intergranular corrosion.The severe intergranular corrosion occurred in the defermed martensite zone.The potentiostatic polarization method can be used to evaluate the intergranular corrosion performance at pulse current crack arresting area of austenitic stainless steels.
作者
张朱武
潘光国
蒋艳
许承伟
ZHANG Zhuwu;PAN Guangguo;JIANG Yan;XU Chengwei(College of Chemical Engineering,Fuzhou University,Fuzhou 350116,China;Fujian Institute of Boiler and Pressure Vessel Inspection Research,Fuzhou 350008,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2020年第3期56-61,77,共7页
Materials For Mechanical Engineering
基金
国家自然科学基金资助项目(51705077)
福建省自然科学基金资助项目(2018J01768)
福州大学贵重仪器设备开放测试基金资助项目(2019T028)。
关键词
304不锈钢
敏化
脉冲电流止裂
晶间腐蚀
304 stainless steel
sensitization
pulse current crack arrest
intergranular corrosion
