| Summary: | The use of high strength steels is increasing steadily due to the cost, weight and performance advantages they offer. As a drawback, these materials are sensitive to environmental hydrogen embrittlement processes that reduce drastically the working loads they can resist, what limits their spreading to many applications. Since this embrittlement is catalyzed by corrosion prevention strategies involving cathodic protection, seawater exposed structures are specially concerned for the attack of hydrogen. Thus, high strength steel use for wet applications must be carefully assessed. In this context, this thesis deals with the study of the hydrogen embrittlement susceptibility of industrial high strength steels for immersed service in mooring chains and bolted joints. Based on the slow strain rate tensile testing method, the influence of cathodic protection and water temperature has been studied for submerged mooring chain steel grades R4, R5 and bolt steel class 10.9. A finite difference modeling strategy for predicting the cracking pattern observed during the experimental work is proposed.
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