DIFFUSION AND SEGREGATION OF HYDROGEN IN MARTENSITIC AISI 5135: INFLUENCE OF BAKING TIME AT 20°C ON THE HYDROGEN DISTRIBUTION AND EMBRITTLEMENT

摘要

The damage occurrence in martensitic steel after hydrogen charging and different baking time at room temperature has been characterized by mechanical testing on smooth specimens and SEM observations. We clearly correlated the rate of hydrogen desorption with a loss of ductility under tensile loading on smooth specimens. The minimum of ductility correspond to quasi-cleavage fracture surface which results to decohesion and/or shearing of martensite laths. Local plastic strain and a high level of hydrogen mobility promote this mechanism.