Effective hydrogen diffusivities of AISI 304 stainless steel with Ni or Au coating

Abstract

Abstract Metallic coatings which provide a hydrogen diffusion barrier are thought to reduce hydrogen assisted cracking on stainless steel. The influence of a metallic layer on the hydrogen migration of AISI 304 stainless steel was investigated using a commercial electroplating layer of Ni and Au on a thin stainless steel coupon. Phase identification was performed using an X-ray diffractometer to determine the average thicknesses, measured from back-scattered scanning electron images. Regarding the ASTM G148-97 practice, the effective hydrogen diffusivities of AISI 304 austenitic stainless steel, nickel and gold were measured as 7.07 × 10-13, 2.72 × 10-14 and 9.64 × 10-16 m2 × s-1, respectively. In this work, a gold layer was found to be most effective for the prevention of hydrogen diffusion when compared with untreated and Ni-plated 304 stainless steel.