中国激光, 2017, 44 (10): 1002003, 网络出版: 2017-10-18
激光沉积修复GH738高温合金的组织与拉伸性能 下载: 728次
Microstructure and Tensile Properties of Laser Deposition Repair GH738 Superalloy
激光技术 激光沉积修复 GH738高温合金 显微组织 拉伸性能 laser technique laser deposition repair GH738 superalloy microstructure tensile property
摘要
对GH738镍基高温合金贯通槽式损伤试样进行激光沉积修复, 分析了修复试样的显微组织及室温拉伸性能。结果表明:激光沉积修复区组织为典型的外延生长柱状枝晶, 枝晶垂直于基体, 并趋向激光沉积高度方向贯穿多个沉积层连续生长, 修复区中心的枝晶取向出现了较大偏转; 修复区内未发现γ′相, 且碳化物含量较少, 枝晶干上主要为富含Cr、Co的颗粒状M23C6型碳化物, 枝晶间存在少量尺寸相对较大的立方体MC型碳化物, 其Ti、Mo含量较高。相比于基体, 热影响区中γ′相的尺寸明显增大, 部分尺寸超过了200 nm, 平均间距明显增大; 热影响区内的碳化物含量减少, 且部分碳化物发生分解。激光沉积修复试样的室温抗拉强度为锻件的78.2%, 断后伸长率为锻件的69.2%。
Abstract
The GH738 nickel-based superalloy through-groove sample is repaired by laser deposition, and the microstructure and room temperature tensile properties of the repaired sample are analyzed. The results show that the microstructure of repair zone presents typical characteristics of columnar dendrite with epitaxial growth, and the dendrites are perpendicular to the substrate and tend to grow along the deposition height direction through multiple layers. The dendritic orientation in the center of the repair area shows a large deflection. No γ′ phase is found in the repair area, the content of carbide in the area is less, the M23C6 type carbides rich in Cr and Co mainly exist in the dendrite stem, and a few cubic MC carbides with relatively larger size and higher contents of Ti and Mo exist among the dendrites. Compared to the substrate, the size of γ′ phase in the heat affected zone obviously increases, the size of partial γ′ phase exceeds 200 nm and the average distance between them increases obviously. The content of carbide in the heat affected zone reduces, and partial carbides decompose. The room temperature tensile strength and elongation of the laser deposition repair sample is 78.2% and 69.2% of those of the forging, respectively.
卞宏友, 翟泉星, 李英, 杨光, 王伟, 王维. 激光沉积修复GH738高温合金的组织与拉伸性能[J]. 中国激光, 2017, 44(10): 1002003. Bian Hongyou, Zhai Quanxing, Li Ying, Yang Guang, Wang Wei, Wang Wei. Microstructure and Tensile Properties of Laser Deposition Repair GH738 Superalloy[J]. Chinese Journal of Lasers, 2017, 44(10): 1002003.