Inconel 625合金TIG-CMT复合堆焊温度场与流场数值模拟  

Numerical simulation of temperature field and flow field of TIG-CMT hybrid cladding for Inconel 625 alloy

作　　者：张超 吴定勇 杨辉 王宁 申俊琦[2,3] 梁瑛[2,3] ZHANG Chao;WU Dingyong;YANG Hui;WANG Ning;SHEN Junqi;LIANG Ying(Tianhe Mechanical Equipment Manufacturing Co.,Ltd.,Suzhou 215557,Jiangsu pro.,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin University,Tianjin 300354,China)

机构地区：[1]中交天和机械设备制造有限公司,江苏苏州215500 [2]天津大学材料科学与工程学院,天津300354 [3]天津大学天津市现代连接技术重点实验室,天津300354

出　　处：《焊接技术》2022年第6期6-12,I0007,共8页Welding Technology

基　　金：国家自然科学基金项目资助(51575381)。

摘　　要：针对Inconel 625镍基合金TIG(钨极氩弧焊)-CMT(冷金属过渡)复合热源堆焊,建立了堆焊过程的数值分析模型,研究了焊接温度场与流场对镍基合金堆敷层润湿性和稀释率的影响规律。结果表明:CMT堆焊时,基材温度梯度大,送丝速度由7.5 m/min提高到9 m/min时,热输入的变化主要影响熔池中心附近3 mm内区域的温度,3 mm外区域温度的升高幅度在50 K以内,熔池边缘及基材温度较低,从而使得镍基合金较难在基材上有效润湿铺展;TIG-CMT复合热源堆焊时,TIG热源预热的主要作用是提高熔池边缘及基材的温度,其中焊缝中心温度基本保持不变,而距焊缝中心3 mm处温度约升高200~300 K,基材温度升高,镍基合金的流动铺展性提高,基材上表面附近的熔池面积明显增大,从而改善堆敷层的润湿性。CMT堆焊时,堆敷层的接触角均>90°,不利于多道堆焊的成形;复合热源堆焊时,堆敷层的接触角<90°,TIG电流为120 A和160 A时,稀释率在5%左右,可以在改善润湿的同时保持较低的稀释率。Aiming at the TIG( Tungsten Inert Gas)-CMT( Cold Metal Transfer) hybrid cladding of nickel based alloy Inconel 625,the numerical analysis model of the cladding process was established, and the influence of welding temperature field and flow field on the wettability and dilution ratio was studied. The results showed that the temperature gradient of the substrate was large during CMT cladding. When the wire feeding speed was increased from 7. 5 m/min to9 m/min,the variation of heat input mainly affected the temperature of the area within 3 mm around the molten pool center,while the temperature of the area outside 3 mm was increased within 50 K. The temperature at the edge of the molten pool and the substrate was low. The solidification of nickel based alloy at the edge of the molten pool resulted in a small increase of the molten pool area. The wettability of nickel based alloy on substrate was poor. During TIG-CMT hybrid cladding,the preheating of TIG heat source mainly improved the temperature of the molten poor edge and the substrate. The temperature at the molten pool center was basically unchanged,while the temperature at 3 mm away from the molten pool center was increased by 200 ~ 300 K. The temperature of the substrate was increased,and the flow spread of nickel based alloy was improved. The molten pool area near the upper surface of the substrate was obviously enlarged,so as to improve the wettability of welding. In CMT cladding,the contact angle of the overlay was more than90°,which was harmful to the formation of multi-passes cladding. In hybrid cladding,the contact angle was less than90°. When the TIG current was 120 A and 160 A, the dilution ratio was kept at 5%, which could improve the wettability and maintain a low level of dilution.

关 键 词：镍基合金 复合堆焊 温度场 润湿性 

分 类 号：TG455[金属学及工艺—焊接]