Numerical evaluation of welding residual stress of X80 pipeline steel under the influence of various welding process parameters

This work aims to improve the durability of the deep-sea transportation pipeline's weld, prolong the pipeline's service life, and ensure the safe and efficient operation of the transportation work. By analyzing the influence of welding parameters on the welding residual stress (WRS) of X80 pipeline steel, the welding process is improved to improve the durability of the welded joint. The WRS of the plate butt joint was measured by the hole-drilling method and X-ray diffraction method; the WRS of the pipe butt joint was measured by the hole-drilling method. The experimental results are compared with the numerical simulation results. The relationship between process parameters and welding residual stress is obtained by simulating WRS of flat plate and circular pipe butt joint under different welding process parameters. The results show that the experimental data measured by X-ray diffraction and the hole-drilling method agree with the results of numerical simulation. The WRS of the two plates decreases with the increase in welding speed and backing thickness, increasing with laminate thickness, welding line energy, and groove angle. The WRS value can be obtained by changing the butt plate welding process, and the WRS value of the tube can be inferred under the same condition.