Effect of Forming Procedure on Residual Stress for Welded Pipe

The residual stress of UOE,JCOE,HSAW welded pipes was investigated with blind-hole method,and the key point was focused on HSAW pipe produced by different processes.The results show that the average biaxial (circumferential and axial)tension stress of UOE welded pipe in the thickness direction was lower than that of JCOE welded pipe,and the maximum residual tension stress located in the inner or outer surface for UOE or JCOE pipe respectively.The average residual stress of HSAW spiral pipe produced with proper forming parametres was close to that of UOE and JCOE longitudinal pipe,but the peak tensile stress value at the inner surface of the spiral pipe was higher.The average residual stress and peak value would be increased greatly by higher forming reduction of the spiral welded pipe.