SURFACE MODIFICATION OF AN AUSTENITIC STAINLESS STEEL SINGLE CRYSTAL BY HYDROGEN CATHODIC CHARGING

摘要

This work proposes to study the residual stresses induced by hydrogen cathodic charging (HCC) in a single crystal of austenitic stainless steel type X2 Cr18Ni12Mo2N0.4. The Vickers Hardness Number (VHN) measurements show the occurrence of the indentation size effect (ISE) and an increase in intrinsic hardness (H_o) with the HCC. The slope (VHN vs. 1/d) depends on the ageing time as a result of the release of residual stresses. X-Ray Diffraction is used to identify the current phases and to follow the stress state in the austenitic single crystal after HCC. The determined stress tensor correspond to hydrostatic pressure. It appears that hardness testing and X-Ray diffraction are complementary tools for the analysis for microstructural effects and residual stresses in HCC steels.