A critical analysis of the fatigue life assessment for arc-welded similar and dissimilar joints in additively manufactured and wrought stainless steel using the peak stress method

Austenitic stainless steels are widely employed in welded structures operating in aggressive environments and, more recently, in assemblies combining wrought (WR) and additively manufactured (AM) components. Despite their industrial relevance, fatigue design procedures for welded joints are still largely derived from data on structural steels and are commonly extended to austenitic stainless steels. This investigation presents a critical analysis of fatigue data for arc-welded austenitic stainless steel joints collected from the literature, with the aim of assessing the transferability of some established fatigue design approaches to this material class. An extensive database of 299 fatigue results was examined, including similar WR–WR welded joints with different geometries and loading conditions, and, where available, welded joints involving AM components in similar (AM–AM) and dissimilar (AM–WR) configurations. The experimental data were first evaluated using the nominal stress approach prescribed by current design standards, and subsequently reanalysed by means of the local, linear elastic Peak Stress Method (PSM). Results indicate that existing design frameworks can yield conservative fatigue life estimations in the high-cycle fatigue regime. However, non-conservative estimations were obtained in the medium- and low-cycle regime, suggesting that greater caution is required when extending fatigue approaches calibrated for structural steels to austenitic stainless steel welded joints.