Comportement en fatigue d'assemblages de divers aciers soudés en utilisant un métal d'apport inoxydable

The fatigue properties of heterogeneous welded joints currently considered in heavy steel fabrication have been investigated, in particular butt welds made with or without buttering of a structural steel to a stainless steel and butt or cruciform welds (load carrying welds and non-load carrying welds) of high-strength steels using stainless steel filler metal.12 mm thick plates were butt or cruciform welded. After characterization of the microstructure and residual stresses (by X rays) for each type of joint, tests were conducted on as-welded, ground or flush-ground (butt welds) joints. The characterization of crack initiation sites and the analysis of results made it possible to identify the parameters which appear to play a dominant role in the fatigue performance of these joints.