Effect of alloying elements on hydrogen diffusion in austenitic stainless steel, Carbon Dissimilar Joints

Diffusion of hydrogen in metals and alloys is effects on material behavior such as loss in mechanical properties. In this work to evaluated the effect of alloying elements on the several chemical composition of the cladding aisi 347 with hydrogen was studied. 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 overlay werewithout 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.