镍基高温合金M17和M38G的电化学腐蚀行为研究  

Electrochemical Behavior of Two Ni-based Superalloys M17 and M38G in Aqueous Solution

作　　者：马敬翙 刘光明[1] 曾潮流[2] 杜楠[1] 赵晴[1] 

机构地区：[1]南昌航空工业学院无损检测技术教育部重点实验室,江西南昌330034 [2]中国科学院金属研究所腐蚀与防护国家重点试验室,辽宁沈阳110015

出　　处：《表面技术》2006年第4期15-17,33,共4页Surface Technology

基　　金：江西省材料研究中心资助项目(ZX200301022;ZX200401009)

摘　　要：采用电化学方法、扫描电镜、能谱分析等技术,研究了常温下镍基高温合金M17和M38G在NaC l溶液和含S2O32-的NaC l溶液中的腐蚀行为。结果表明,在含质量分数为3.5%NaC l的溶液中,M17和M38G均会遭受严重的点腐蚀;向NaC l溶液(NaC l质量分数为3.5%)添加Na2S2O3(Na2S2O3质量分数为1.5%)后,由于溶液中的S2O32-在试样表面活性点与C l-竞争吸附并与H+结合,使两种合金的点蚀均受到抑制;M38G中存在微量的Nb、Ta、Mo等元素使得M38G合金在NaC l溶液中的耐腐蚀性能明显优于M17合金。Corrosion behaviors of nickel-based superalloys M17 and M38G are investigated in NaCl solution and NaCl ＋ Na2S2O3 solutions at room temperature by electrochemical techniques. The microstructure and compositions of the tested samples are investigated by SEM/EDS. The results show that M17 and M38G suffer from serious pitting corrosion in 3.5 wt. % NaC1 solution. However, when two superalloys tested in 1.5 wt. % Na2S2O3 ＋ 3.5 wt. % NaCl solutions, the pitting corrosion is inhibited, which resulted from S2O3^2- integrating with H^＋ and decreasing the electromigration of Cl^- into the pits from the buck solution. In 3.5 wt. % NaC1 solution, the corrosion resistance of M38G alloy is better than that of M17 alloy for small amount of Nb, Ta, Mo existed in M38G alloy.

关 键 词：镍基 高温合金 点蚀 电化学方法 腐蚀行为 

分 类 号：TG172.5[金属学及工艺—金属表面处理]