热处理对Inconel718镍基合金组织及耐蚀性能的影响

Influence of Heat Treatment on Microstructure and Corrosion Resistant Performance of Inconel718 Nickel-Base Alloy

研究了Inconel718合金在940~1 000℃固溶以及固溶＋时效处理（720℃保温8 h后经50℃/h冷却到620℃保温8 h）后的组织及性能之间关系。结果表明,固溶处理后合金的硬度随着温度的升高而减小。固溶＋时效处理后合金的硬度随着温度的升高先是增大再减小,到980℃时达到最大值,且硬度值比仅固溶处理的增加约1倍。在用H2SO4溶液调节pH值（pH=3）的体积分数为5%Na2SO4酸性溶液中测试极化曲线和交流阻抗,结果表明,固溶＋时效处理样品的耐蚀性比仅固溶处理的差。在模拟高温高压H2S/CO2应力腐蚀环境试验测试结果表明,固溶处理和固溶＋时效处理的样品耐H2S/CO2应力腐蚀性能均较好。

The relation between microstructure and corrosion resistant performance on Incone1718 nickel--base alloy which were solution treated at 940-1 000 ℃ as well as solution treated and then aged at 720 ℃ for 8 h, 50 ℃/h cooling and 620 ℃ for 8 h, was researched. The result show that the rigidity of alloy declined with solution temperature increasing. After solution and aging, the rigidity of alloy raised firstly then declined with temperature increasing, and reached the maximum at 980 ℃, the rigidities were the double of solution. Polarization curve and Alternating Current impedance were tested in 5% Na2SO4 acidity liquor which was regulated to pH of 3 with H2 SOn liquor. The result indicate that the corrosion resistant performance of samples which is solution treated and aged is worse than solution treated only. The simulation test at the high temperature and pressure H2S/CO2 stress corrosion condition indicated that the H2S/CO2 stress corrosion resistant performance of samples which are solution treated as well as solution treated and aged are both good.