激光沉积修复GH738高温合金的组织与拉伸性能

发布时间：2018-12-07 10:23

【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M_(23)C_6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200nm,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]:Laser deposition and repair of GH738 nickel-base superalloy through trough damage samples were carried out. The microstructure and tensile properties at room temperature of the repaired specimens were analyzed. The results show that the microstructure of laser deposition repair zone is a typical epitaxial growth columnar dendrite perpendicular to the substrate and tends to grow continuously in the direction of laser deposition height through multiple deposition layers. The dendritic orientation in the center of the repair zone appears a large deflection. No 纬 'phase was found in the repair zone, and the content of carbides was low. The dendritic stem was mainly composed of granular M _ (23) C _ 6 carbide rich in Cr,Co. There were a few cubic MC type carbides with relatively large size between the dendrite and their Ti,. The content of Mo is high. Compared with the matrix, the size of 纬 'phase in the heat affected zone is obviously increased, some of the size of 纬' phase is larger than 200 nm, the average spacing is obviously increased, and the carbide content in the heat affected zone decreases and some carbides decompose. The tensile strength at room temperature is 78.2 of the forgings, and the elongation after break is 69.2 of the forgings.
【作者单位】：沈阳航空航天大学航空制造工艺数字化国防重点学科实验室;中国航发沈阳黎明航空发动机有限责任公司焊接研究所;
【基金】：国家自然科学基金(51375316) 航空科学基金(2014ZE54028) 辽宁省自然科学基金(20170540690)
【分类号】：TG132.3

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