Ti2AlNb钛合金电子束焊温度场与应力场有限元分析

Finite Element Analysis of Temperature Field and Stress Field of Ti2AlNb Titanium Alloy during Electron Beam Welding

基于有限元软件,采用高斯面-高斯旋转体复合热源深入研究了Ti2Al Nb钛合金电子束焊接头的温度场和残余应力场。结果表明:当电子束流为10 m A,焊接速度为360 mm/min时焊接接头成型较好,优先采用较大电子束流易形成熔宽较大的焊缝。焊缝内部应力为复杂三向应力状态,残余应力以纵向拉应力为主,集中分布于距焊缝中心3.5mm范围内。焊后最大等效应力为635 MPa,小于材料屈服强度,较为安全。

The temperature field and residual stress field of Ti2AlNb titanium alloy electron beam welding joint were studied by using Gaussian surface and rotary body composite heat source based on finite element software.The results show that the welding joint is well formed when the electronic beam current is 10 mA and the welding speed is 360 mm/min.It is preferred to use a big electron beam current to form welded seam with large weld width.The central area of the weld suffers complex stresses in three directions,and the residual stress is mainly longitudinal tensile stress,which is concentrated within 3.5 mm from the weldline.The maximum equivalent stress after welding is 635 MPa,which is less than the yield strength of the material,so the structure is safe.