【摘要】 钛合金因其优良的性能得到广泛应用,其材料的焊接特点及其结构在使用过程中的安全可靠性问题也越来越引起人们的关注,目前钛合金已成为载人深潜器耐压球壳的首选材料。本文首先对Ti80对接焊厚板残余应力进行了数值模拟以及X射线无损检测试验研究,在得到数值模拟结果后将其与试验测量值进行对比,结果吻合较好,即Ti80对接焊厚板表面横向残余拉应力呈现不对称双峰;焊缝中心线上的纵向残余拉应力较大;焊缝处沿板厚方向的内部横向残余应力和垂向残余应力在近上下表面处均为拉应力,且横向残余应力高于垂向残余应力,沿板厚方向均呈现拉应力-压应力-拉应力趋势。然后基于热弹塑性有限元分析方法,对Ti80耐压球壳赤道焊缝焊接残余应力进行数值模拟研究,得到赤道焊缝表面残余应力和内部残余应力分布规律。结果显示:Ti80耐压球壳内壳表面有较大的残余拉应力;纵向残余拉应力大于横向残余拉应力;球壳外表面有较大的横向残余压应力,而纵向残余应力为拉应力。更多还原

【Abstract】 Titanium alloy has been widely used because of its excellent properties. The welding characteristics of titanium alloy and the safety and reliability of its structure in service have attracted more and more attention. At present, titanium alloy has become the preferred material for spherical pressure shells of manned deep submersibles. In this paper, the residual stress of a Ti80 butt welded thick plate was measured with method of non-destructive X-ray and obtained by numerical simulation analysis. The results of experiment and simulation were in good agreement. The transverse residual tensile stress of the Ti80 butt welded thick plate exhibited an asymmetric bimodal distribution, and the longitudinal residual tensile stress along the weld center line was higher. The internal transverse residual stress and the internal vertical residual stress along thickness direction of the weld seam were tensile stress near the upper and lower surfaces, and the transverse residual stress was higher than the vertical residual stress. The residual stress along the thickness direction showed a trend of the tensile stress near the surface and the compressive stress in the middle. Then, the residual stress of equatorial weld of the Ti80 spherical pressure shell was numerically simulated with the method of thermal elastic-plastic analysis, and the distribution rules of the residual stress of the surface and the internal residual stress of the equatorial weld of the Ti80 spherical pressure shell were obtained. The results show that(1) the residual stress of the inner surface of the Ti80 spherical pressure shell is higher tensile stress;(2)the longitudinal residual tensile stress is greater than the transverse residual tensile stress;(3) the transverse residual stress of the outer surface of the spherical shell was higher compressive stress; and(4) the longitudinal residual stress was tensile stress.更多还原