国产825合金的耐腐蚀性能研究

Corrosion Resistance Properties of Domestic 825 Alloy

采用腐蚀失重法、电化学测试和慢应变速率拉伸应力腐蚀研究了国产825合金在HCl、NaOH和NaCl溶液中的腐蚀行为,并采用金相显微镜和扫描电镜(SEM)对腐蚀后的样品进行观察。结果表明,国产825合金在HCl溶液中浸泡7 d后发生了明显的腐蚀,腐蚀速率随HCl浓度的增加而增大,而在NaOH和NaCl溶液中浸泡5个月后未发生明显腐蚀,并且在HCl、NaOH和NaCl溶液中合金的腐蚀电流随溶液浓度增加而增大。慢应变速率拉伸应力腐蚀结果表明在HCl、NaOH和NaCl溶液中合金的应力腐蚀敏感性很小,因此,一般情况下不会发生应力腐蚀开裂。

Corrosion behaviors of domestic 825 alloy in HC1, NaOH and NaCI solutions were studied by corrosion mass loss, electrochemical test and stress corrosion at slow strain rate. Meanwhile, the corrosion morphologies were investigated by optical microscopy and scanning electron microscopy （SEM）. The results showed that the corrosion behavior of the domestic 825 alloy was not obvious after immersion in NaOH and NaC1 solutions for 5 months. However, it corroded evidently after immersion in HC1 solution for 7 d, and the corrosion rate in HCI solution increased with increasing HC1 concentration. Furthermore, the corrosion current of the domestic 825 alloy increased with increasing concentration of HCI, NaOH and NaCI solution, respectively. The stress corrosion tests at slow strain rate showed that the domestic 825 alloy had no stress corrosion susceptibility in the HC1, NaOH and NaC1 solution, thus no stress corrosion crack would occur under normal circumstance.