Impact of Laser Shock Peening on Hydrogen Embrittlement Resistance: The Role of Residual Stresses

Hydrogen embrittlement is a significant problem for the durability and safety of materials used in hydrogen-rich environments, such as in energy storage, transportation, and aerospace industries. It leads to premature failure of structural materials, making it crucial to develop effective methods to mitigate this phenomenon. While Laser Shock Peening (LSP) has been shown to enhance material properties by inducing compressive residual stresses, its effects on hydrogen embrittlement resistance have not been extensively studied. This research addresses this gap by systematically comparing the impact of five different sets of LSP parameters on the hydrogen embrittlement resistance of steels.

The study utilizes three complementary methods—X-ray Diffraction (XRD), Contour Method, and ESPI Hole Drilling—to analyze residual stress profiles and their correlation with hydrogen embrittlement behavior. XRD provides information on the residual stress distribution in the surface layers, while the Contour Method and ESPI Hole Drilling offer detailed, depth-dependent stress profiles. The complementarity of these techniques allows for a comprehensive assessment of the effects of LSP on the material’s stress state and hydrogen embrittlement resistance.

In addition to measuring residual stresses, this study also investigates the microstructural changes induced by LSP and their influence on hydrogen atom migration. While previous studies have focused primarily on the increase in hardness following LSP and its role in reducing hydrogen atom migration, our approach highlights how different LSP parameters modify residual stresses in a way that directly influences hydrogen embrittlement resistance. The results suggest that LSP, by altering the residual stress state, can significantly improve the material’s resistance to hydrogen-induced cracking, offering a promising method for enhancing the durability of materials exposed to hydrogen.