Abstract
Studies have been carried out to assess the effect of residual stresses and deformations arising in the process of assembly and welding, as well as after metal cooling, on the shape of pipes. In the process of cooling, the weld and heat-affected sections are shortened, leading to a curvature of their generatrices, with the main change noted at the ends of pipes. To determine the stresses and strains in pipes, experimental and analytical studies and mathematical modeling were carried out at the assembly and welding site. Presented are the results of geometry measurements from the front and rear ends of pipe blanks and pipes with dimensions of 1420×25; 1420×21.6; 1420×18.7; 1420×15.7 mm of K60 strength class and 813×39; 813×37.4 and 813×39 mm of K65 strength class after step forming, assembly, welding and expansion, as well as the curvature of these pipes. The calculation of stress intensity along the entire perimeter of pipes 813×39 and 1420×25.8 mm before and after assembly on the assembly and welding mill was carried out. Pipes with a ratio of diameter to wall thickness of 90.4 of the K60 strength class had the largest deviation in ovality and curvature, and the smallest deviations were 20.8 and 22.3 of the K65 strength class. After welding of the external seams, the vertical diameter and the value of curvature increase, and after expansion they decrease. The total change in the ovality of pipes due to residual welding deformations is on average 0.5% for pipes with a diameter of 813 mm and 2% for pipes with a diameter of 1420 mm.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call