热处理工艺对FSW和TIG焊影响的有限元数值模拟
发布时间：2019-05-20 12:55
【摘要】：焊接过程中,焊核区内构件将经历剧烈的高温作用并产生极大的塑性应变,这种变形是极其不均匀的。在不均匀的形变作用下,结构将产生焊接热应力并最终形成焊后残余应力,影响构件的强度及疲劳寿命。工程中为了降低构件在焊接制造过程中产生的焊接残余应力,常采用热处理的方式对焊后残余应力进行消除。本文首先采用顺序热力耦合方法,运用有限元软件ABAQUS及其子程序对焊接过程进行模拟。研究中对比分析了FSW、TIG焊接过程的温度场、焊后残余应力场,讨论了热输入功率对两种焊接方式的影响,并对焊后残余应力进行了热处理。计算结果表明：FSW焊接过程峰值温度为1062℃,远低于TIG焊接的1683℃,仅为熔点温度70%；焊核区内FSW焊接拉伸应力数值低、分布范围小,深度方向上应力呈下降趋势,较TIG焊接更为合理；增大两种焊接方式的热输入,焊后残余应力均有略微下降；焊后热处理可以有效的降低焊接残余应力,热处理温度越高,降低效果越明显。本文还在平板焊接的基础上,进行了工程压缩机叶轮的焊接计算。在对焊接过程的模拟分析中,研究了叶轮焊接的温度场、焊接残余应力场,并讨论了叶轮几何尺寸对焊接过程的影响。随后为了降低叶轮内的焊后残余应力,以保证正常服役过程中的强度及疲劳性能,进行了焊后热处理计算,系统研究了焊后热处理温度、热处理保温时间等工艺参数对降低焊后残余应力的影响。计算结果表明：叶轮焊接温度场集中于焊道两侧,远离焊缝位置各点温升并不明显,叶片延焊接方向焊后拉伸残余应力峰值将达到1138MPa,垂直焊接方向残余应力也将达到783.9MPa；轮盘厚度越大,热应变越小,焊后残余应力越大；叶片厚度增大,热应变减小,焊后残余应力出现不规律变化；焊后热处理有效的降低了焊后叶轮内的残余应力,热处理温度越高,残余应力越低,但当温度过高时,叶片边缘与轮盘接触位置将因过度变形产生不合理的应力集中；保温时间越长,应力松弛效果越好,焊后残余应力降低越明显。
[Abstract]:In the welding process, the components in the welding core zone will undergo severe high temperature action and produce great plastic strain, which is extremely uneven. Under the action of uneven deformation, the structure will produce welding thermal stress and finally form the residual stress after welding, which will affect the strength and fatigue life of the component. In order to reduce the welding residual stress of components in the process of welding and manufacturing, heat treatment is often used to eliminate the residual stress after welding. In this paper, the sequential thermodynamic coupling method is used to simulate the welding process by using the finite element software ABAQUS and its subroutine. In the study, the temperature field and residual stress field of FSW,TIG welding process are compared and analyzed, the influence of heat input power on the two welding methods is discussed, and the residual stress after welding is heat treated. The results show that the peak temperature of FSW welding process is 1062 鈩，
本文编号：2481655
[Abstract]:In the welding process, the components in the welding core zone will undergo severe high temperature action and produce great plastic strain, which is extremely uneven. Under the action of uneven deformation, the structure will produce welding thermal stress and finally form the residual stress after welding, which will affect the strength and fatigue life of the component. In order to reduce the welding residual stress of components in the process of welding and manufacturing, heat treatment is often used to eliminate the residual stress after welding. In this paper, the sequential thermodynamic coupling method is used to simulate the welding process by using the finite element software ABAQUS and its subroutine. In the study, the temperature field and residual stress field of FSW,TIG welding process are compared and analyzed, the influence of heat input power on the two welding methods is discussed, and the residual stress after welding is heat treated. The results show that the peak temperature of FSW welding process is 1062 鈩，
本文编号：2481655
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