脱敏时间对690合金晶界贫铬区演变及晶间腐蚀倾向的影响

Effect of Desensitization Time on Evolution of Chromium-Depleted Zone and Intergranular Corrosion Tendency of 690 Alloy

通过TEM、相分析及EPR的方法,研究了脱敏时间对690合金相析出规律、贫铬区演变及晶间腐蚀倾向的影响。结果表明,在700℃脱敏0.5-20 h,M23C6析出优先顺序为晶界、孪晶端部、位错缠结处,随着脱敏时间的增加,690合金的M23C6析出量增加,其贫铬区的最低铬含量显著提高,晶间腐蚀倾向明显降低,其700℃最佳脱敏时间为10-20 h。

Effect of desensitization time on phase precipitation,evolution of chromium-depleted zone and intergranular corrosion tendency of Inconel 690 alloy was studied in this paper through TEM,phase analysis and EPR methods.With increase of desensitization time at 700℃,the results can be obtained as follows： the precipitated priority of M23C6 is from grain boundary,end of compound twin to place of dislocation tangling;with M23C6 amount increasing,the lowest chromium content in chromium-depleted zone raises and intergranular corrosion tendency decreases significantly;the range of optimum desensitization time at 700℃ is 10-20h.