Failure assessment of seam-welded pipe under fatigue and thermal loading

• This paper presents an assessment of the failure of a seam-welded pipeline under fatigue and thermal loading. • Both experimental analysis and numerical simulations utilizing the finite element method (FEM) were conducted to understand potential failure modes of a seam-welded SS304L pipeline. • The experimental analysis explored different aspects of failure, such as stress corrosion cracking, welding defects, and the impacts of thermal and fatigue loading, as well as overloads. • The numerical simulations investigated weld defects, residual stresses, fatigue and thermal loading, and the propagation of fatigue cracks. • It is concluded that the primary cause of failure was linked to suboptimal welding procedures and post-welding treatment, along with the presence of high levels of residual stresses in the heat-affected zone (HAZ) of the weld. This paper presents an assessment of the failure of a seam-welded pipeline under fatigue and thermal loading. The investigation concentrated on analyzing several factors potentially influencing pipeline failure. Both experimental analysis and numerical simulations utilizing the finite element method (FEM) were conducted to understand potential failure modes of a seam-welded SS304L pipeline. The experimental and FEA analyses investigated various failure factors including weld defects, fatigue and thermal loading, residual stresses, and overloads. The study concludes that substandard welding procedures and inadequate post-weld treatment, coupled with elevated residual stresses in the heat-affected zone (HAZ) of the weld, were the primary contributors to failure. The paper systematically outlines the utilization of experimental and FE analyses in examining practical engineering failure instances. This approach strengthens the ability to avert failures and navigate risks with precision. Furthermore, the results highlight the critical significance of adhering to code and standard guidelines concerning pipe seam welds and post-weld treatment practices.