Hydrogen-damaged defects of heavily deformed Fe, AISI 304-, and 316-stainless steels were investigated by measuring Doppler broadening energy spectra of positron annihilation radiation. It was found that the S-parameter as a function of energy on 3 kinds of deformed samples fell into the similar variation, independent of chemical elements and impurities. A larger S value near the surface in deformed and H-damaged samples than in samples without H-damaged samples was because of the additional larger-sized defects (e.g. voids) induced due to H damage.

Hydrogen-Damaged Defects Near the Surface in Heavily Deformed Iron and Steels Investigated by Slow Positron Annihilation Spectroscopy. Y.C.Wu, Y.C.Jean: Physica Status Solidi C, 2007, 4[10], 3506-9