Effect of Alloying Elements on Hydrogen diffusion in dissimilar joint of Austenitic stainless steel/Carbon steel

Diffusion of hydrogen in metals and alloys will affect the material behavior such as loss in mechanical properties. In this research the effect of alloying element on the hydrogen diffusion of the cladding AISI 347 with several different chemical compositions has been evaluated. For this purpose a piece of carbon steel St37 was prepared and cladding with filler metal with two different chemical compound 347 stainless steel. In this regard، a non-hazardous electrochemical charging method to hydrogen charge the specimens.. Mechanical properties and microstructure of the specimens were studied by means of micro hardness testing، tensile strength، toughness، optical microscopy and microanalysis techniques (EDS). Results indicate that both overlays were without any defects in the interfaces. Also the results of the cladding samples showed the presence of elements such as Cr، Mn، Ti، Nb can reduce hydrogen permeation and diffusion، while Ni probability can increase permeation and hydrogen embrittlement.