(1. 沈陽(yáng)航空航天大學(xué) 航空制造工藝數(shù)字化國(guó)防重點(diǎn)學(xué)科實(shí)驗(yàn)室，沈陽(yáng) 110136；
2. 中國(guó)航發(fā)沈陽(yáng)黎明航空發(fā)動(dòng)機(jī)有限責(zé)任公司 焊接技術(shù)室，沈陽(yáng) 110043)
摘 要: 采用GH536合金粉末對(duì)GH738合金損傷試樣進(jìn)行激光沉積修復(fù)試驗(yàn)研究，通過(guò)正交試驗(yàn)法優(yōu)化工藝參數(shù)，得到較小熔深、無(wú)缺陷的修復(fù)試樣；測(cè)試分析了修復(fù)試樣的顯微組織、室溫拉伸性能及顯微硬度。結(jié)果表明：合金修復(fù)區(qū)為外延生長(zhǎng)的柱狀晶組織，修復(fù)區(qū)邊緣柱狀晶取向較一致，修復(fù)區(qū)中心柱狀晶出現(xiàn)一定角度轉(zhuǎn)向；合金修復(fù)區(qū)枝晶干上主要為富含Mo、Cr的M6C碳化物，晶界處出現(xiàn)少量細(xì)小的M23C6碳化物。相比于基體，合金熱影響區(qū)中γ′相數(shù)量減少并呈粗化趨勢(shì)，MC碳化物發(fā)生分解。激光沉積修復(fù)試樣室溫抗拉強(qiáng)度為GH738鍛件的66.5%，高于 GH536鍛件強(qiáng)度；斷后伸長(zhǎng)率分別低于GH738鍛件及GH536鍛件的；修復(fù)區(qū)域的顯微硬度分別低于GH738基體的顯微硬度，高于GH536鍛件的顯微硬度。
關(guān)鍵字: GH536合金；GH738合金；激光沉積修復(fù)；顯微組織；拉伸性能；顯微硬度
（1. Key Laboratory of Fundamental Science for National Defence of Aeronautical Digital Manufacturing Process, Shenyang Aerospace University, Shenyang 110136, China;
2. Welding Research Institute, Shenyang Liming Aero-Engine Corporation LTD, AECC, Shenyang 110043, China）
Abstract:The GH536 alloy power was used for the laser deposition repair of the GH738 damage specimen, and the flawless specimen with a small weld depth was obtained through orthogonal test. The microstructure, room temperature tensile properties and microhardness of the repair specimens were analyzed. The results show that the microstructure of repair zone is columnar dendrite with an epitaxial growth. The columnar dendrite at the edge of repair zone shows an uniform orientation, and that at the center of repair zone appears a certain angle of rotation .In the repair zone, the M6C carbides rich in Mo, Cr are mostly at dendrite stem, and a small amount of fine M23C6 carbides are found at grain boundary. Compared with the substrate, the amount of γ′ phase in heat-affected zone decreases obviously, the size of γ＇phase shows a coarsening tendency, and the MC carbides decompose. The tensile strength at room temperature of the laser deposition repair specimens is approximately 66.5% of the GH738 forgings, and it is higher than that of GH536 forgings. The elongation of the laser deposition repair specimens is lower than that of GH738 forgings and GH536 forgings, respectively. The microhardness of repair zone is lower than that of GH738 substrate, and slightly higher than that of GH536 forgings.
Key words: GH536 alloy; GH738 alloy; laser deposition repair; microstructure; tensile property; microhardness
