Effect of Welding Sequence and Hydrotest Process on Welding Residual Stresses in Stainless Steel SUS304 Pipes

علوم کاربردی و محاسباتی در مکانیک

Article 2, Volume 22, Issue 2, December 2011, Pages 17-34   

Document Type: Original Article

DOI: 10.22067/fum-mech.v22i2.10613

Authors

Mohammad Mashayekhi^* ; Hadi Hedayati

Abstract

In the present study, temperature fields and residual stress states in the weld joint of the stainless steel pipe are computed numerically using a thermo-elastic-plastic analysis. This weld joint is a circumferential butt-weld one and is done in two passes using gas tungsten arc welding. Welding procedure is simulated in two and three dimensions using a subroutine developed in finite element ABAQUS software for applying heat flux. Furthermore, the element birth and death technique is used to simulate weld passes and filler metal deposition into the weld pool. When the simulation is done, the effect of welding sequence on welding residual stresses are considered using four different welding sequences proposed. Finally, the effect of hydrotest process in decreasing the residual stresses is evaluated. The results of the simulation show that selecting a suitable welding sequence can substantially decrease the amount of tensile residual stresses and can change them to compressive stresses in certain situations. Also the results of this research show that applying a hydrotest pressure after welding process can reduce welding residual stresses up to 65%.

References