FEM modeling of softened base metal in narrow-gap joint by CMT+P MIX welding procedure  

冷金属过渡复合脉冲焊接(CMT+P)窄间隙焊接头基体软化现象的有限元模拟(英文)

作　　者：舒凤远[1,2] 吕耀辉[2] 刘玉欣[2] 徐富家[1,2] 孙哲[2] 何鹏[1] 徐滨士[1,2] 

机构地区：[1]哈尔滨工业大学先进焊接与连接技术国家重点实验室,哈尔滨150001 [2]装甲兵工程学院再制造技术重点实验室,北京100072

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第6期1830-1835,共6页中国有色金属学报（英文版）

基　　金：Project (9140C850205120C8501) supported by the Major Program of National Key Laboratory of Remanufacturing and the Army Foundation Project of China

摘　　要：A required finite element method（FEM） model applicable for narrow gap CMT and CMT＋P MIX welding was established based on the interactions between arc,base metal and filler metal.A novel method of simplifying wire feeding pulses and heat input pulses was supposed under the conduction of equivalent input.The method together with composed double-ellipse heat sources was included in the model.The model was employed in the investigation of thermal cycling and the identification of the softened zone of AA7A52 base plates.Low-frequency behavior emerged in the form of low-cooling rate sects,which were not expected under experimental conditions.The softened zone including the quenched zone and averaging zone of the base plate was much wider internal the base plate than that close to the surfaces.The reliability of the predictions in thermal cycling was supported by infrared imaging test results of the thermal cycle process.根据电弧对基体材料及填充材料的作用过程建立了CMT和CMT+P过程的有限元模型,其中基于等效热输入原则简化了CMT焊接过程中焊丝进退和热输入之间的相互作用过程。对热源的处理中,采用复合双椭球热源模型。基于该有限元模型研究了热循环规律,由此划分出AA7A52母材的焊接热影响区。模拟计算结果与实验结果的不同之处是,冷却过程中出现低频效应,这种低频效应的表现方式为低冷却速率。软化区包括淬火区和过时效区,基板内部的软化范围明显大于基板近表层区域。通过红外测温实验验证了计算模拟结果的准确性。

关 键 词：cold metal transferring finite element method equivalent input low-cooling rate sects softened zone 

分 类 号：TG407[金属学及工艺—焊接]