Li Yu, Hou Jia-Yi, Zheng Wen-Jian, Wan Zheng-Quan, Tang Wen-Yong
China Ship Scientific Research Center, Wuxi 214082, China.
Department of Chemical Machinery, College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310000, China.
Materials (Basel). 2022 Apr 14;15(8):2882. doi: 10.3390/ma15082882.
A prediction model of the welding process of Ti-6Al-4V titanium alloy was established by using the finite element method, which was used to evaluate the phase composition, residual stress and deformation of the welded joints of Ti-6Al-4V sheets with different processes (including tungsten inert gas welding, TIG, and laser beam welding, LBW). The Ti-6Al-4V structures of TIG welding and LBW are widely used in marine engineering. In order to quantitatively study the effects of different welding processes (including TIG welding and LBW) on the microstructure evolution, macro residual stress and deformation of Ti6Al4V titanium alloy sheets during welding, a unified prediction model considering solid-state phase transformation was established based on the ABAQUS subroutine. In this paper, LBW and TIG welding experiments of 1.6 mm thick Ti-6Al-4V titanium alloy sheets were designed. The microstructure distribution of the welded joints observed in the experiment was consistent with the phase composition predicted by the model, and the hardness measurement experiment could also verify the phase composition and proportion. From the residual stress measured by experiment and the residual stress and deformation calculated by finite element simulation of LBW and TIG weldments, it is concluded that the effect of phase transformation on residual stress is mainly in the weld area, which has an effect on the distribution of tensile and compressive stress in the weld area. The overall deformation of the welded joint is mainly related to the welding process, and the phase transformation only affects the local volume change of the weld seam. Importantly, the phase composition and residual stress, which are scalar fields, calculated by the established model can be introduced into the numerical analysis of structural fracture failure as input influence factors.
采用有限元方法建立了Ti-6Al-4V钛合金焊接过程的预测模型，用于评估不同工艺（包括钨极惰性气体保护焊、TIG焊和激光束焊、LBW焊）下Ti-6Al-4V板材焊接接头的相组成、残余应力和变形。TIG焊和LBW焊的Ti-6Al-4V结构广泛应用于海洋工程。为了定量研究不同焊接工艺（包括TIG焊和LBW焊）对Ti6Al4V钛合金板材焊接过程中微观组织演变、宏观残余应力和变形的影响，基于ABAQUS子程序建立了考虑固态相变的统一预测模型。本文设计了1.6mm厚Ti-6Al-4V钛合金板材的LBW焊和TIG焊试验。试验观察到的焊接接头微观组织分布与模型预测的相组成一致，硬度测量试验也能验证相组成和比例。从试验测量的残余应力以及LBW焊和TIG焊焊件有限元模拟计算得到的残余应力和变形可知，相变对残余应力的影响主要在焊缝区域，对焊缝区域拉应力和压应力的分布有影响。焊接接头的整体变形主要与焊接工艺有关，相变仅影响焊缝的局部体积变化。重要的是，所建立模型计算得到的作为标量场的相组成和残余应力可作为输入影响因素引入到结构断裂失效的数值分析中。
