【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。更多还原

【Abstract】 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.% NaCl solution.However,when two superalloys tested in 1.5 wt.% Na₂S₂O₃ + 3.5 wt.% NaCl solutions,the pitting corrosion is inhibited,which resulted from S₂O^2-₃ integrating with H⁺ and decreasing the electromigration of Cl^-into the pits from the buck solution.In 3.5 wt.% NaCl 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.更多还原