Title
Analysis of Hydrogenation Effects, Degree of Deformation, and Degradation Mechanisms in 316L Stainless Steel Sheets Subjected to Severe Plastic Deformation
Code
52610317
Start year
2026
End year
2027
Provider
Visegrad Fund
Category
Projekt
Type
Visegrádské granty
Summary
The project focuses on analyzing the behavior of 316L stainless steel, with an emphasis on determining the quantitative relationships between the degree of deformation, the resulting microstructure (grain size, dislocation structure, deformation-induced phases), and the extent of deterioration in mechanical properties and fracture toughness caused by hydrogen.
In the first stage, 316L steel sheets and, if appropriate, selected comparative steels will be processed using the forming equipment, including severe plastic deformation techniques such as DRECE or related prototype tools. These processes enable large plastic strains to be formed in strip form, leading to refined microstructures and significantly modified mechanical properties, which are ideal for studying the effect of prior strain on the hydrogen uptake and embrittlement phenomena.
In the second stage, samples with different deformation histories will be subjected to electrochemical charging under controlled conditions of temperature, time, and potential or pressure, followed by tensile tests, hardness measurements, and, where possible, fracture mechanics tests.
Comparisons between charged and uncharged samples will allow the determination of changes in yield strength, ultimate tensile strength, uniform and total elongation, reduction of area, and overall fracture behaviour as a function of hydrogen content and prior deformation.
The third stage will consist of detailed microstructural and fractographic analyses using advanced characterisation techniques, including SEM, EBSD and X-ray diffraction.
These methods will be used to examine the phase composition, grain refinement, crystallographic texture, dislocation arrangements, and morphology of fracture surfaces, enabling identification of preferred crack paths and mechanisms such as hydrogen-enhanced localised plasticity (HELP) and hydrogen-enhanced decohesion (HEDE).
A final and important part of the work will be to compare the behaviour of 316L stainless steel with that of other steels processed by similar severe plastic deformation routes. This comparison will help clarify the influence of phase stability, stacking fault energy, and microstructural refinement on hydrogen susceptibility, and will contribute to guidelines for designing steels and processing routes for components operating in hydrogencontaining environments.