激光焊接及焊后热处理K439B合金的显微组织与力学性能  

Microstructure and mechanical properties of laser welded and post-weld heat-treated K439B superalloy

作　　者：李郑 张振林 吴爱萍[1,2,4] 张明军[5] 康举 刘瞿[1,2] 赵玥[1,2] 陈晶阳[5] Zheng LI;Zhen-lin ZHANG;Ai-ping WU;Ming-jun ZHANG;Ju KANG;Qu LIU;Yue ZHAO;Jing-yang CHEN(Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;Key Laboratory for Advanced Materials Processing Technology,Ministry of Education,Tsinghua University,Beijing 100084,China;School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Tribology,Tsinghua University,Beijing 100084,China;Science and Technology on Advanced High Temperature Structural Materials Laboratory,Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Higher Institution Engineering Research Center of Energy Engineering Advanced Joining Technology,Beijing Institute of Petrochemical Technology,Beijing 102617,China)

机构地区：[1]清华大学机械工程系,北京100084 [2]清华大学先进材料加工技术教育部重点实验室,北京100084 [3]西南交通大学材料科学与工程学院,成都610031 [4]清华大学摩擦学国家重点实验室,北京100084 [5]北京航空材料研究院先进高温结构材料重点实验室,北京100095 [6]北京石油化工学院北京能源工程先进连接技术高等学校工程研究中心,北京102617

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第3期905-917,共13页中国有色金属学报（英文版）

基　　金：the financial support from the National Science and Technology Major Project of China (No. J2019-VI-0004-0117);National Natural Science Foundation of China (No. 51905301)。

摘　　要：对应用于发动机涡轮上的新型镍基合金K439B进行激光焊接实验,研究焊后热处理对接头显微组织和力学性能的影响。半定量分析结果表明,热处理后接头各区域γ′相均发生长大,一次γ′相和二次γ′相半径分别约为25和150 nm。力学性能测试结果表明,焊后热处理可使焊缝区硬度提高约HV 100,由γ′相提供的临界恢复剪应力从4.8 MPa提高到92 MPa;另一方面,热处理后接头的抗拉强度和屈服强度与母材的相当,大量碳化物的存在导致接头在拉伸过程中优先断裂于母材处。Laser welding of the new nickel-based alloy K439B applied for engine turbine was carried out.The effects of post-welding heat treatment(PWHT)on the microstructure and mechanical properties of the joints were investigated.Semi-quantitative statistical results show that after PWHT,γ'phases in the whole joint grow up,and the radii of the primary and secondaryγ'phases are about 25 and 150 nm,respectively.The results of mechanical properties show that PWHT improves the microhardness in the weld by about HV 100,and the critical resolved shear stress provided byγ'phases increases from 4.8 to 92 MPa.The tensile strength and yield strength of the heat-treated joint are comparable to those of the base metal.The presence of a large amount of carbides is the reason for the preferential fracture of the base metal during the tensile process.

关 键 词：镍基高温合金 激光焊接 γ'相 碳化物 显微组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接] TG441.8[一般工业技术—材料科学与工程] TG132.3[金属学及工艺—合金]