高温水中溶解氧、氯离子和处理方式对316L不锈钢应力腐蚀性能的影响

Effects of Dissolved Oxygen,Chloride and Treatment on Stress Corrosion Behavior of 316L SS in High Temperature Pure Water

采用慢应变速率试验(SSRT),在模拟压水堆核电厂高温高压水环境(325℃、15.5 MPa)中,研究了溶解氧(DO)、氯离子和处理方式对316L不锈钢(SS)的应力腐蚀开裂(SCC)倾向的影响规律,并观察了试样断口形貌。结果表明,冷变形和固溶处理的316L不锈钢分别在含0μg/kg DO+0μg/kg Cl-,200μg/kg DO+0μg/kg Cl-,0μg/kg DO+30μg/kg Cl-及200μg/kg DO+30μg/kg Cl-的高温水环境中都呈现出了不同程度的SCC倾向,且200μg/kg DO和30μg/kg Cl-使SCC倾向更为明显。同时,冷变形可大大提高316L不锈钢的屈服强度,但是也提高了SCC敏感性。

The effects of DO, Cl and treatment on the SCC behavior of 316L SS were srudied by SSRT in high temperature （325 ℃） and high pressure （15. 5 MPa） environments and the fracture morphology of specimens after testing was observed carefully. The results showed that both cold worked and solution treated 316L SS had SCC susceptibility in high temperature water environments containing 0μg/kg DO＋0μg/kg Cl , 200 μg/kg DO＋0 μg/ kg Cl-, 0μg/kg DO＋30μg/kg Cl- or 200μg/kg DO＋30μg/kg Cl . And the effect of 200 htg/kg DO and 30μg/ kg Cl- on SCC susceptibility was very remarkable. Although cold work could enhance the yield strength of 316L SS, it increased the SCC susceptibility of 316L SS.