摘要
用电化学动电位再活化法测得的反向扫描电流的最大值与正向扫描电流的最大值的比值（ｉｒ／ｉａ）评价各种敏化程度的３０８Ｌ不锈钢的晶间腐蚀敏感性。结果表明：在不出现过敏化条件下，比值ｉｒ／ｉａ与材料的敏化程度有良好的对应关系；随着敏化处理温度的提高和敏化时间的延长，电流比值ｉｒ／ｉａ增大。电化学动电位再活化法可以灵敏并且定量地评价３０８Ｌ不锈钢的晶间腐蚀敏感性，并且与草酸实验中得到的金相评级有对应性，ｉｒ／ｉａ≤２．９７×１０－３对应草酸浸蚀实验中的“阶梯”组织，２．９７×１０－３＜ｉｒ／ｉａ＜１．４８×１０－２对应“混合”组织，ｉｒ／ｉａ≥１．４８×１０－２对应“沟状”组织。
The degree of sensitization (DOS) in 308L stainless steel has been measured through determing the ratio of the maximum current generated by the reactivation scan to that of the anodic scan i r/i a in double loop (DL) electrochemical potentiodynamic reactivation(EPR) test. The results indicated that, based on the EPR test, all the DOSs used in this study can be differentiated except for the occurance of desensitization. With increasing sensitization time at a certain temperature or sensitization temperature for a certain duration, the current ratio measured from EPR test increased. DL EPR technique provides a sensitive, quantitative, nondestructive method for detecting the degrees of sensitization which match the metallographic ratings obtained by the oxalic acid etch test. The current rations were in the range of ≤2.98×10 -3 for step structures, between 2.98×10 -3 to 1.48×10 -2 for dual structures, and ≥1.48×10 -2 for ditch structures.
出处
《腐蚀科学与防护技术》
CAS
CSCD
1996年第2期87-93,共7页
Corrosion Science and Protection Technology
关键词
敏化
晶间腐蚀
不锈钢
电化学
动电位
degree of sensitization, EPR test, oxalic acid etch test, intergranular corrosion, stainless steel
