Analysis of Hydrogen in Cathodically Polarized Austenitic Stainless Steels

When hydrogen atoms penetrate into stainless steels, hydrogen embrittlement sometimes occurs. So, the behavior of hydrogen dissolved in the stainless steels around room temperature must be investigated. We have investigated the penetration of hydrogen into the austenitic stainless steels of SUS304, SUS310S and SUS316L by cathodic polarization. The specimens were cathodically polarized in an H_2SO_4 Solution. Immediately after interruption of cathodic current, hydrogen analysis was done by the thermal desorption spectroscopy method. In thermal spectra of hydrogen evolution of these stainless steel specimens, two hydrogen evolution peaks were observed at 40℃ and 230-260℃, irrespective of cathodic polarization time. And, these peaks became large with increase in cathodic polarization time, while the peak temperatures of these peaks were almost constant. These experimental results indicate that hydrogen is introduced into the austenitic stainless steels by cathodic polarization, and that there are two kinds of the potential energy of dissolved hydrogen