Influence of Metallurgical and Mechanical States on the Diffusion and Trapping of Hydrogen in Quenched and Tempered Martensitic Steels

Influences of the microstructure of quenched and tempered martensitic steels on the diffusion and trapping of hydrogen under different mechanical states are investigated. Different steels were compared in terms of microstructural parameters that could interact with hydrogen. Electrochemical permeation and thermal desorption spectroscopy performed at different temperatures permit to define the hydrogen diffusion and trapping features. Good agreements were obtained between electrochemical permeation modeling and experimental results deduced from TDS. Hydrogen trapping and diffusion can be discussed in relation with microstructural features (vacancy, dislocation, precipitate, geometrically necessary boundary…) and mechanical states (elastic and microplastic regimes).