核级316LN不锈钢焊接接头在高温高压水中的腐蚀性能研究

Corrosion Property of Nuclear Grade 316LN Stainless Steel Weld Joint in High Temperature and High Pressure Water

利用扫描电镜、X射线衍射和X射线光电子能谱等分析手段并结合腐蚀增重测量,研究了核级316LN不锈钢焊接接头在高温高压水中的氧化膜变化情况和抗腐蚀性能。结果表明:随着腐蚀周期的增加,腐蚀增重先降低,随后缓慢增加至稳定状态;焊接接头表面氧化膜的主要成分为FeOOH,FeCr_2O_4和Fe_3O_4;316LN不锈钢焊接接头中焊缝区具有与母材区相当的耐均匀腐蚀性能。

The corrosion performance of weld joints of nuclear grade stainless steel in high temperature and high pressure water was investigated by means of mass change measurement,scanning electron microscope(SEM),X-ray diffractometer(XRD)and X-ray photoelectron spectroscopy(XPS).The results showed that,in the initial stage before 340 h,the weld joints suffered from mass loss with a relative high rate,then the mass loss turned to decrease gradually,finally the weld joint exhibited a little mass gain when the test reached 1080 h and hereafter the mass gain kept at a stale level.The oxide scale formed on the weld joints consisted of FeOOH,FeCr2O4 and Fe3O4 primarily.In conclusion,the weld seam of 316LN stainless steel exhibited an equivalent resistance to uniform corrosion as the base metal.