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Die Untersuchung von Oberflächen und Volumendefekten in Stahl nach elektrolytischer Wasserstoffsättigung

: Chernov, I.; Cherdantzev, Y.; Lider, A.; Garanin, G.; Kröning, M.; Baumbach, H.

WOM 2001 Wodorodnaja Obrabotka Materialow. Bearbeitung von Materialien mit Wasserstoff. Bd.2
Donetzk-Mariupol, 2001
Internationale Konferenz "Bearbeitung von Materialien mit Wasserstoff" <3, 2001, Donetzk-Mariupol>
Conference Paper
Fraunhofer IZFP ()
Stahl; Oberfläche; Wasserstoffsättigung

The data on influence of hydrogen concentration in stainless steel 316 upon defects formation and defects accumulation during hydrogen electrolytic charge from LiOh+H2O solution are presented. The regularities of surface damages in dependence on electrolysis time at current densities in a range 0,5-1 A/cm2 was studied. Hydrogen charge less than 1 hour and current densities up to 1 A/cm2 surface erosion is not detected. At charging three hours were found the folowing modifications of a surface: a) detection of borders grains of metal; b) a buckling of seperate areas of a surface; c) flacking of metal plates of ungeometrical in dimension up to 100 mm. Dynamics of defects accumulation on depth from 0 to 150 mm have been studied by positrons annihilation method. It is revealed that the average value of a positrons life-time slowly varies in depending on hydrogen concentration. The two-component decomposing of a spectrum of positrons life-time has shown a low intensity of a long-lived component conforming to presence of a large-size defects. It testifies that lattice of stainless steel is stability to implanted hydrogen at a selected velosity of a hydrogen charging. The obtained results allow to make a conclusion that a bulk destruction of metal grains is not occurs. At the same time, the hydrogen is actively connecting with carbides on borders of grains, therefore there is exhibiting of borders grains. These outputs are confirmed by a method of thermo-waves microscopy. The destruction on grains borders may be made by a reaction of hydrogen with impurities, which are precipiate on borders, for example, with carbon.