Fatigue Crack Propagation in Welded Joint

Welded joints are often subjected to fatigue type of loading which results in the initiation and propagation of a dominant crack. Thus characterization of crack growth behaviour in weld metal, heat affected zone and base metal is very important to evaluate the relative strength of the joint. The crack growth in weld metal is very much dependent on the residual stress pattern and so the fatigue strength of weldment may be inferior or superior to the base metal depending on the location of the defect and type of loading applied. These aspects of the problem are discussed in detail in the present paper.