三元催化器筒段环缝焊接温度场及应力场数值模拟分析  

Numerical simulation and analysis for temperature field and stress field of girth weld in three-way catalyst cone section

作　　者：高树灵 李云涛[1] 马蒙蒙[1] 褚亮[1] 

机构地区：[1]天津理工大学材料科学与工程学院,天津300384

出　　处：《焊接技术》2017年第5期12-17,共6页Welding Technology

基　　金：天津市科技特派员项目(15JCTPJC64400)

摘　　要：以筒体直径为114 mm的三元催化器筒段环缝为研究对象,根据三元催化器实际设计结构,运用MSC.marc软件对三元催化器筒体与上、下盖环缝焊接进行有限元模拟分析,分别采用1 000,2 000,3 000,4 000 W热输入功率模拟计算,得到了焊接过程的温度场分布及最终残余应力场分布,结果表明,随着热输入功率增大,残余应力场面积也随之增大,在热输入功率为1 000 W时,2个结构的最大残余应力分别为290 MPa和285 MPa。在筒体弯曲部分出现了很大的变形,主要原因是筒体材料使用的是409不锈钢,该不锈钢在室温下屈服强度为240 MPa,焊接残余应力太大,引起弯曲位置变形较大。根据焊接模拟结果,本次模拟为实际焊接夹具设计和焊接工艺参数的制订提供了理论指导。The girth weld of three-way catalyst with 114 mm diameter was as the research object.According to the actual design structure of the three-way catalyst,the finite element simulation analysis was made on the cylinder with the upper and lower cover of the three-way catalyst which has girth weld by using MSC.marc software.By using1 000,2 000,3 000,4 000 W welding heat input power simulation,which had obtained the distribution of temperature field and the distribution of residual stress field in the welding.The results showed that the residual stress field increased with the increase of heat input power.When the heat input power was 1 000 W,the maximum residual stress of the two structures were 290 MPa and 285 MPa.And in the tube bending part had large deformation,the main reason was that the cylinder material was 409 stainless steel.409 stainless steel at room temperature yield strength was 240 MPa,the welding residual stress was too large,large deformation caused by bending position.According to the welding simulation results,this simulation provided a theoretical guidance for the design of the actual welding fixture and welding process parameters.

关 键 词：三元催化器 环缝焊接 有限元模拟 温度场 残余应力场 

分 类 号：TG406[金属学及工艺—焊接]