钛合金具有高强耐蚀、易焊等优质性能，广泛用于潜艇、深潜器等潜水器的受力构件及耐压耐蚀壳体。在焊接过程中，会不可避免的产生焊接残余应力，较大的焊接残余应力会影响焊接结构的安全性能，而焊后热处理能够有效减少焊接残余应力。本文首先采用数值模拟的方法对TC4对接焊平板热处理前后的残余应力进行计算，通过与试验结果进行对比研究，验证有限元数值模拟的合理性；然后采用该数值模拟方法研究Ti80对接焊平板多层多道焊的整个焊接过程以及焊后热处理方法。结果表明，焊后Ti80对接焊平板表面具有较大横向和纵向残余拉应力，通过热处理工艺后，残余拉应力得到明显降低。因此，通过焊后热处理方法可以在很大程度上降低对焊接结构力学性能可能产生的不利影响的残余拉应力。
Titanium alloy with high performance such as high strength corrosion resistance and easy welding. It is widely used in force components, pressure and corrosion resistant shells of submarines, deep submersibles and other submersibles. During the welding process, residual stress would inevitably occur, and the safety property of the welding structure would be effected by larger welding residual stress, and the welding residual stress could be effectively reduced by post weld heat treatment (PWHT). In this paper, the residual stress of the TC4 flat butt welding joint before and after PWHT is firstly simulated. Through a comparative study with test results, the rationality of the finite element numerical simulation is verified. Then, this numerical simulation method is used to study the entire welding process and PWHT of Ti80 flat butt joint with multi-layer welding. The results show that there are large transverse and longitudinal residual tensile stress in the surface of Ti80 flat butt welding joint, and the residual tensile stress is obviously reduced after PWHT. Therefore, the residual tensile stress which could affect the mechanical properties of welding structure is reduced to a great extent by PWHT.
2021,43(2): 31-35 收稿日期：2020-04-04
DOI：10.3404/j.issn.1672-7649.2021.02.006
分类号：TG404
基金项目：国家重点研究发展计划资助项目(2017YFC0305501)
作者简介：李良碧(1971-),女,教授,研究方向为船舶与海洋结构物
参考文献：
[1] 蒋文春, 王炳英, 巩建鸣. 焊接残余应力在热处理过程中的演变[J]. 焊接学报, 2011, 32(4): 45-48, 115
[2] 姜云禄, 余陈, 陈静, 等. 钛合金窄间隙TIG焊试板热处理前后表面残余应力研究[J]. 航空制造技术, 2018, 61(8): 62-66
[3] 余陈, 张宇鹏, 房卫萍, 等. 焊后热处理对100 mm TC4钛合金电子束焊接头残余应力的影响[J]. 材料热处理学报, 2018, 39(7): 151-155
[4] YAN G, CRIVOI A, SUN Y, et al. An Arrhenius equation-based model to predict the residual stress relief of post weld heat treatment of Ti-6Al-4V plate[J]. Journal of Manufacturing Processes, 2018, 32: 763-772
[5] 闻雅. TC4钛合金球壳体电子束焊接接头性能及应力分析[D]. 哈尔滨：哈尔滨工业大学, 2014.
[6] 李有华, 刘智宇, 王新, 等. 热处理对TA15钛合金厚板残余应力的影响研究[J]. 中国钛业, 2015(3): 15-17
[7] 金俊龙, 万晓慧, 郭德伦. TC17钛合金焊接及局部热处理残余应力的数值模拟[J]. 航空制造技术, 2019, 62(12): 30-35
[8] ANDRADE E N C. On the viscous flow in metals, and allied phenomena[J]. Proceedings of the Royal Society of London.Series A, Containing Papers of a Mathematical and Physical Character, 1910, 84(567): 1-12
[9] DORN J E. Some fundamental experiments on high temperature creep[J]. Journal of the Mechanics and Physics of Solids, 1955, 3(2): 85
[10] FIELDS B A, FIELDS R J.Elevated temperature deformation of structural steel[R]. Gaithersburg: National Institute of Standards and Technology, 1989.
[11] NORTON F H.The creep of steel at high temperatures[M]. New York: McGraw-Hil Inc., 1929.
[12] LIU Chuan, LUO Ying, YANG MIN, et al. Three-dimensional finite element simulation of welding residual stress in RPV with two J-groove welds[J]. Welding in the World, 2017, 61(1): 151-160
[13] 王伟, 李华冠, 杨吟飞, 等. Ti6Al4V钛合金薄板退火畸变数值模拟及试验验证[J]. 金属热处理, 2016, 41(1): 204-210
[14] Al-MUKHTAR, A.M. Consideration of the residual stress distributions in fatigue crack growth calculations for assessing welded steel joints[J]. Fatigue & Fracture of Engineering Materials & Structures, 2013, 36(12): 1352-1361
[15] 黄伯云, 李成功, 石力开, 等. 中国材料工程大典第四卷, 有色金属材料材料工程(上册)[M]. 北京: 化学工业出版社. 2005.
[16] 张建勋, 刘川著. 焊接应力变形有限元计算及其工程应用. 北京: 科学出版社, 2015. 04.
[17] GJB 3763A-2004, 钛及钛合金的热处理[S].
