Mechanical and electrochemical alteration of sorbitic and austenitic steels charged with hydrogen

Abstract

Experiments made with the method initiated by Hyspecka and Mazanek have revealed phenomena not encountered with other methods of investigation, such as the recovery of mechanical properties while still discharging, and the simultaneous effect on electrochemical voltage, which can only be due to a trasformation of the hydrogen state inside the metal. It was also observed experimentally that those processes are generalized, may be iterative, and occur for times correlated with the density of discharge.

An attempt was also made, with very significant results, to correlate the variation in these mechanical properties, depending on the hydrogen charging time, with the much more easily achieved variation in electrochemical characteristics. Study of these phenomena was combined with examination of the fracture surfaces and numerous longitudinal diametral sections under the fractures, using a Cambridge 600 scanning electron microscope (SEM). The results for sorbitic steels were published as they became available (2-8) and an interpretative model was proposed based on them; the new results for austenitic steels, and for electrochemical tests, also seem capable of being referred to that model.