钛合金薄板TIG焊的固态相变及残余应力数值仿真计算研究  

Numerical Simulation of Solid Phase Transformation and Residual Stress in TIG Welding of Titanium Alloy Sheet

作　　者：郦羽[1] 阚甜甜 万正权[1] 唐文勇[2] LI Yu;KAN Tiantian;WAN Zhengquan;TANG Wenyong(China Ship Scientific Research Center,Wuxi 214082,China;School of Naval Architecture,Ocean and Civil Engineering,Shanghai JiaoTong University,Shanghai 200240,China)

机构地区：[1]中国船舶科学研究中心,无锡214082 [2]上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《中国造船》2022年第5期53-70,共18页Shipbuilding of China

摘　　要：为了揭示焊接工艺对焊接接头组织成分、残余应力分布和变形的影响,以及它们之间的相互关系,基于固态相变理论,采用JMAK方程和K-M方程建立Ti6Al4V钛合金固态相变数学模型,应用Abaqus软件开发考虑固态相变的热-组织-力耦合的有限元计算方法,采用该模型对1.6mm厚的Ti6Al4V钛合金薄板进行TIG焊接的有限元计算。为了验证计算模型的准确性及残余应力的分布规律,对焊接接头进行硬度和残余应力测量。结果表明,焊接接头硬度的分布规律与仿真结果的微观组织成分的分布规律一致,不仅验证了模型的准确性,而且很好地解释了焊接接头组成成分的差异及α相、α′马氏体相和β相的性能差异对宏观力学性能的影响;通过对测量的残余应力和观测的变形与仿真结果比较,发现α相和β相热力学性能的差异以及焊接接头中α相和β相组成比的差异对残余应力分布和变形的影响显著。该研究对于优化钛合金焊接工艺参数,改变焊缝的组织成分,改善焊接接头的力学性能具有工程指导意义。In order to reveal the influence of the welding process of Ti6Al4V titanium alloy sheet on the microstructure, residual stress distribution and deformation of the welded joint, and on their relationships, a mathematical model of the solid-state phase transformation for Ti6Al4V titanium alloy is established by using JMAK equation and K-M equation. A thermal-metallurgical-mechanical coupled finite element method considering solid-state phase transformation is developed with the software ABAQUS. The model is used to calculate the TIG welding of Ti6Al4V titanium sheet with the thickness of 1.6mm. In order to verify the correctness of the calculation method and the distribution regularity of residual stress, hardness test and residual stress measurement of TIG welded joints of Ti6Al4V titanium alloy with thickness of 6mm were carried out respectively. Measured hardness distribution regularity of the welded joint is consistent with the microstructure composition distribution regularity of the simulation results. It not only verifies the correctness of the model, but also explains the composition difference in microstructure of welded joints and the performance difference between phase α, phase α′ and phase β, and their influence on the macro mechanical properties. By comparing the measured residual stress and observed deformation with the simulation results, it can be found that the significant difference in the thermodynamic properties of phase αand phase β and the difference in the composition ratio of phase α and phase β of welded joints have a significant impact on the residual stress distribution and deformation. This study has guiding significance for optimizing the welding process parameters of titanium alloy, changing the microstructure composition of the weld seam and improving the mechanical properties of welded joints.

关 键 词：钛合金 钨极惰性气体保护焊 固态相变 残余应力 数值模拟 

分 类 号：TG404[金属学及工艺—焊接]