Corrosion fatigue of welded high-strength cast and structural steel joints under constant and variable amplitude loading

Structures of offshore platforms are generally subjected to high loads. These structures are mainly fabricated from steel with welded complex tubular steel nodes where fatigue cracking occurs in the weld toe, weld undercut or in the weld due to stress concentrations. Greater sea depths lead to higher loads and therefore major efforts have been devoted to the development of hybrid design concepts combining rolled steel with cast steel inserts. This paper discusses the results of fatigue tests of cast/structural steel joints under free corrosion as well as under cathodic protection for constant and variable amplitude loading.