Abstract
The surface of a 316 stainless steel (316SS) specimen was nitrided by an electrochemical treatment in molten fluoride salt. Its hydrogen permeability was evaluated and compared with that of bare 316SS at temperature from 450◦C to 650◦C. When it was exposed to hydrogen pressure of 1.0 kPa from 450◦C to 650◦C, its permeability was 7.2×10−11 to 6.4×10−12 mol/sec.m.Pa1/2. The permeation flux was increased with temperature and the permeability is deviated from Sieverts’ law around 450◦C. It followed Sieverts’ law and was similar to that of bare 316SS at elevated temperatures. This result suggested the surface nitriding increases solubility at low temperatures around 450◦C.