海水泵泵轴腐蚀分析与改进

Corrosion analysis of seawater pump shaft and its improvement

为解决船用海水泵漏水、不上水故障,拆检海水泵,发现泵轴表面严重腐蚀、剥落,造成海水泵叶轮脱落、泵轴密封失效。对故障海水泵泵轴进行电镜分析、能谱分析、金相分析,确定泵轴腐蚀原因为3Cr13与退火状态下耐海水腐蚀能力较弱;选取5组耐海水腐蚀材料进行对比分析,选取固溶、620℃时效处理的05Cr17Ni4Cu4Nb与退火状态3Cr13进行盐雾、海水浸泡试验对比。试验结果表明:05Cr17Ni4Cu4Nb耐海水腐蚀能力远高于3Cr13,可以满足海水泵使用工况。经过10个月的市场验证,未出现海水泵漏水、不上水故障。

In order to solve the problem of leakage and water supply interruption of marine seawater pump,the seawater pump is disassembled and inspected.It is found that the surface of the pump shaft is seriously corroded and peeled off,resulting in the impeller falling off and the seal failure of the pump shaft.The failure of seawater pump shaft is analyzed by electron microscope,energy spectrum analysis and metallographic analysis.It is found that 3Cr13 has weak seawater corrosion resistance under annealing condition.Five groups of seawater corrosion-resistant materials are selected for comparative analysis.3Cr13 in annealed state is compared with 05Cr17Ni4Cu4Nb in salt spray and seawater immersion tests.The test results show that 05Cr17Ni4Cu4Nb has much higher seawater corrosion resistance than 3Cr13,which can meet the service conditions of seawater pump.After 10 months of market verification,there is no leakage and no water supply fault of seawater pump.