Effect Of Hydrogen On Stainless Steel Photocurrent Response

Since stainless steel has good corrosion resistance and high strength performance,it is one of the most important structural materials in petroleum industry, chemicalindustry, aerospace and nuclear industry. In these industries, stainless steel is used inhydrogen environment. Superior corrosion resistance of stainless steel is related to itssurface passivation film, the passivation film obvious semiconductor properties, so tostudy the effect of hydrogen on stainless steel of the photocurrent response haveimportant significance.The polarization curve is used to determine the sample passivation zone in boratebuffer solution after dc passivation. Plotted the M-S curves to analyze semiconductorcharacteristics of the surface passive films under different passivation potential.Specimens were precharged for different hydrogen current density and then the testside of the specimens was passivated. In order to study the hydrogen on thesemiconductor characteristics of the passive film, the Mitt-Schottky (M-S) curvemethod was used. The (Iphhv)1/2-photon energy curves were performed using thecurrent method, to analyze the effect of hydrogen the surface passive film structure,semiconductor type and the band gap of compound layers.Results show that the corrosion potential of stainless steel304is0.265V,passivation area from0.2V to1.0V, the studies of semiconductor properties of the304stainless steel passive films are conducted in the passivation zone. The donorconcentration of304stainless steel is decreased, while the flat band potential isincreased with the increment of passive potential. The specimens passivated on the600mv, acceptor concentration and the flat band potential are maximum. Hydrogenincreases donor concentration, decreases acceptor concentration and results in morenegative flat band potential. The influence of hydrogen on the electronic propertybecomes more noticeable with increasing hydrogen-charging current densities. Thetime of passivation has no effect on304stainless steel passivation film semiconductortype. Hydrogen has almost no effect on the optical band gap of passive films on304stainless steel. According to the optical band gap,the composition of passive film maybe: the inner layer for Cr2O3、FexNi1-xCr2O4, outer layer of Fe2O3.