Effects of Welding Parameters, Time Interval and Preheating on Residual Stress and Distortion of Joining St52 Stiffener Ring in an Aisi 4130 Tubular Shell

Abstract

Stiffener rings and stringers are used commonly in offshore and aerospace structures. Welding the stiffener to the structure causes the appearance of residual stress and distortion that leads to short-term and long-term negative effects. Residual stress and distortion of welding have destructive effects such as deformation, brittle fracture, and fatigue of the welded structures. This paper aims to investigate the effects of preheating, time interval and welding parameters such as welding current and speed on residual stress and distortion of joining an ST52-3N (DIN 1.0570) T-shape stiffener ring to an AISI 4130 (DIN 1.7218) thin-walled tubular shell by eleven pairs of welding line in both sides of the ring by means of finite element method (FEM). Results in tangent (longitudinal), axial and radial directions have been compared and the best welding methods proposed. After the comparison of the results, simultaneous welding both sides of the ring with preheating presented as the best method with less distortion and residual stresses among the studied conditions. The correctness of the FEM confirmed by the validation of the results.

Effect of Welding Speed on Residual Stress and Distortion of AISI 1045 Plate Using the Finite Element Method (FEM)

“…Therefore, it can be assumed that lower welding speed will affect to improve total residual stress occurred during welding process. In AISI 1045 plate welding process owns two directional residual stress within longitudinal and transverse direction [10]. Longitudinal residual stress develops in the same direction of welding process which occurred in x-axis.…”