Abstract Effect of solution heat treatment on microstructure and electrochemical behavior was investigated for the electron beam smelted (EBS) 718 superalloy. The results imply that the solution heat treatment has a great influence on the precipitation behavior of EBS 718 superalloys and thus affects the electrochemical behavior. The increase of solution temperature gives rise to the solution of δ phase for both solution treated and aged EBS 718 superalloys. The 980 °C solution treated and aged EBS 718 superalloy exhibits the maximum content of the volume fraction of γʹʹ phase, in parallel with the highest lattice misfits. Further increase of solution temperature results in the precipitation of dispersively distributed γʹ particles. The pitting potential for the solution treated superalloys increases gradually with increase of solution temperature, and a similar behavior is observed for the aged superalloys with an exception of the alloy processed at 980 °C. The effect of solution temperature on the solution treated superalloys can be elucidated by considering the variation of the volume fraction and the size of δ precipitates. For the aged superalloys, the deterioration effect of Nb rich γʹʹ is obvious due to the tetragonal distortion and accompanying strain field in the nearby matrix. Higher solution temperature results in a uniform distribution of the nano-scale γʹ phase and smallest lattice misfits, with the highest apparent activation energy derived to be 52.86 kJ/mol.

中文翻译：

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固溶热处理对电子束熔炼Inconel 718高温合金组织和电化学行为的影响

摘要 研究了固溶热处理对电子束熔炼 (EBS) 718 高温合金组织和电化学行为的影响。结果表明，固溶热处理对 EBS 718 高温合金的析出行为有很大影响，从而影响电化学行为。固溶温度的增加导致固溶处理和时效 EBS 718 高温合金的 δ 相溶解。980 °C 固溶处理和时效的 EBS 718 高温合金显示出最大的 γʹʹ 相体积分数含量，同时具有最高的晶格失配。溶液温度的进一步升高导致分散分布的γ′颗粒沉淀。固溶处理高温合金的点蚀潜力随着固溶温度的升高而逐渐增加，除了在 980 °C 下加工的合金外，时效高温合金也观察到类似的行为。固溶温度对固溶处理高温合金的影响可以通过考虑δ相的体积分数和尺寸的变化来阐明。对于时效高温合金，由于附近基体中的四方畸变和伴随的应变场，富铌γʹʹγ′的劣化效应明显。较高的固溶温度导致纳米级 γʹ 相的均匀分布和最小的晶格失配，最高表观活化能为 52.86 kJ/mol。固溶温度对固溶处理高温合金的影响可以通过考虑δ相的体积分数和尺寸的变化来阐明。对于时效高温合金，由于附近基体中的四方畸变和伴随的应变场，富铌γʹʹγ′的劣化效应明显。较高的固溶温度导致纳米级 γʹ 相的均匀分布和最小的晶格失配，最高表观活化能为 52.86 kJ/mol。固溶温度对固溶处理高温合金的影响可以通过考虑δ相的体积分数和尺寸的变化来阐明。对于时效高温合金，由于附近基体中的四方畸变和伴随的应变场，富铌γʹʹγ′的劣化效应明显。较高的固溶温度导致纳米级 γʹ 相的均匀分布和最小的晶格失配，最高表观活化能为 52.86 kJ/mol。