Abstract: The specimen were made of imported structural steel A537 and Chinese structural steel E36 in the stress state of hot point modeling joints. According to the maximum likelihood principle, the experiments were designed. The following were investigated the effects of materials, environment (air, seawater), welding procedure (as-welded or post-welded treatment) for fatigue strength of welded joints and got P-S-N curves. In comparison with the results of the fatigue experiments of the pipeline joints. It was indicated that the view that the fatigue life of welded joints was equal to the initiating life of fatigue experiments of pipeline joints was conservative.

Key words: Fatigue life, Initiating life, Low-cycle fatigue, Offshore structure, Welded joint