固溶温度对ZK60镁合金耐腐蚀性能的影响

Effect of Solution Temperature on Corrosion Resistance of ZK60 Magnesium Alloy

在不同温度(200~300℃)下对铸态ZK60镁合金进行固溶处理,采用扫描电子显微镜观察不同温度固溶后合金的显微组织,并采用质量损失法和电化学方法研究了不同温度固溶后合金在质量分数为3.5%NaCl溶液中的耐腐蚀性能。结果表明:随着固溶温度的升高,合金中第二相的含量减少且由连续分布变为不连续分布;随着固溶温度的升高,合金的腐蚀速率先升高后降低;经300℃固溶处理后,ZK60镁合金的耐腐蚀性能最好,其腐蚀速率为4.575 2mm·a^(-1),自腐蚀电流密度和自腐蚀电位分别为0.011 639mA·cm^(-2)和-1.511 0V。

ZK60 magnesium alloy was solution-treated at different temperature（200-300 ℃）.The microstructure was observed by scanning electron microscope（SEM）and corrosion resistance of the alloy in mass fraction of 3.5% NaCl solution was studied by the mass loss method and electrochemical method.The results indicate that the content of second phase in the alloy decreased with the increase of solution temperature,and the distribution of second phase changed from continuity into discontinuity.The corrosion rate increased first and then reduced with the increase of solution temperature.The optimal corrosion resistance was obtained at solution temperature of 300 ℃,and the corrosion rate,free corrosion current density and free corrosion potential were 4.5752 mm·a^-1,0.011 639 mA·cm^-2,-1.511 0 V,respectively.