固溶热处理对GH3535合金组织和性能的影响

Effect of solution heat treatment on microstructure and properties of GH3535 superalloy

摘要:

对热轧态GH3535合金进行不同温度和时间的固溶处理,采用扫描电子显微镜 (SEM)、电子背散射衍射技术(EBSD)和拉伸试验等手段研究了固溶处理后的合金组织及其对力学性能的影响。经过1177℃/20min固溶热处理后,合金发生再结晶与晶粒长大,一次M₆C碳化物发生部分溶解。在更高温度下 (1220℃和1260℃) 固溶热处理后,晶粒异常长大且一次M₆C碳化物数量明显减少。随着固溶温度的提高和固溶时间的延长,合金的抗拉强度随之降低,而延伸率提高。结合组织分析和断口分析发现,不同固溶热处理后合金的拉伸性能的变化源于晶粒的长大和一次M₆C碳化物的溶解。

Abstract:

The effect of solution heat treatment on the microstructure and properties of hot-rolled GH3535 superalloyhas been investigated by Scanning Electron Microscope (SEM), Electron Back scattered Diffraction (EBSD) and tensile tests. Significant grain growth and carbide dissolution occur after solution treated at 1177°C for 20min. With the rise of the solution temperature up to 1220°Cand 1260°C, the grain size grows abnormally and the amounts of M₆C carbides decrease significantly.Tensile tests indicated that higher solution temperature and longer solution time lead to the decrease of ultimate tensile strength and the improvement of elongation. The grain growth and carbide dissolution are responsible for the evolution of tensile properties in GH3535 superalloy after different solution heat treatments.