Effect of hydrogen trapping on hydrogen permeation in a 2205 duplex stainless steel: Role of austenite–ferrite interface

Hydrogen diffusion and interactions with structural defects are fundamental for understanding and regulating the hydrogen embrittlement of steels. The hydrogen permeation in deformed 2205 duplex stainless steel (DSS) is systematically investigated through experiments, numerical simulations, and novel theoretical models. The hydrogen diffusivity of 2205 DSS is insensitive to plastic deformation, but is markedly affected by the phase boundary and ferrite grain boundary. Phase boundaries not only act as strong hydrogen traps; but also make hydrogen diffusion paths more tortuous owing to the diffusion energy barrier at the interface. Hydrogen binding energy at the austenite-ferrite interface is approximately 43.6 kJ/mol. • Hydrogen permeation in 2205 duplex stainless steel was studied. • The H diffusivity of the deformed steel is insensitive to plastic strains. • Austenite-ferrite interface is the main hydrogen trap. • The interface also acts as hydrogen diffusion barrier for hydrogen transport.