GH536镍基高温合金焊接接头力学性能与断裂特征研究  

Mechanical Properties and Fracture Characteristics of Welded Joint in GH536 Ni-based Superalloy

作　　者：魏振伟[1,2,3] 刘昌奎[1,2,3] 顾玉丽[1,2,3] 陶春虎[1,2,3] 

机构地区：[1]北京航空材料研究院,北京100095 [2]中航工业失效分析中心,北京100095 [3]航空材料检测与评价北京市重点实验室,北京100095

出　　处：《航空材料学报》2015年第5期70-74,共5页Journal of Aeronautical Materials

摘　　要：对GH536合金焊接接头的硬度进行测试和分析,对母材及焊接接头进行室温和500℃拉伸试验,并分析了断裂特征,分析了母材和焊接接头不同区域的断裂韧度。结果表明:热影响区硬度未见明显变化,与母材一致;从熔合线到焊缝中心,由于枝晶变细,显微硬度逐渐升高。焊接接头整体室温拉伸强度、屈服强度和断后伸长率分别为810MPa,392MPa和30%,达到了母材的99.6%,99.7%和93.8%;在500℃时,接头整体抗拉强度、屈服强度和断后伸长率分别为678MPa,300MPa和26%,达到了母材的98.1%,96.8%和78.8%;GH536合金焊接接头具有良好的力学性能。在熔合区组织不均匀性最为严重,熔合区是GH536合金焊接接头的薄弱环节。在室温和500℃,母材及焊接接头的断裂方式均为塑性断裂。Microhardness,tensile properties and fracture toughness of based metal and different zones in welded joint for GH536 obtained by gas tungsten arc welding（ GTAW） were studied. The results show that hardness in HAZ is equal to BM,however,hardness becomes higher from fusion line to weld center for finer dendritic structures. The tensile strength σb、yield strength σsand elongation δat room temperature（ RT） are 810 MPa,392MPa and 30%,which reach 99. 6%,99. 7% and 93. 8% of based materials＇,respectively; The σb,σsand δ at 500℃ are 678 MPa,300MPa and 26%,which reach 98. 1%,96. 8% and 78. 8% of based materials＇,respectively; The welded joint of GH536 has good mechanical properties. Fusion zone is the weak link of welded joint for higher microstructure heterogeneity. Based metal and welded joint break mainly in the way of plastic rupture both at RT and 500℃.

关 键 词：镍基高温合金 钨极氩弧焊 显微硬度 拉伸性能 断裂韧度 裂纹尖端张开位移 

分 类 号：TG113[金属学及工艺—物理冶金]