In steam turbines, blades operate in a high-speed wet steam environment and are often damaged by combined erosion from liquid droplets and solid particles. To reveal the mechanism of composite modification via high velocity oxy-fuel spraying (HVOF) and laser shock peening (LSP) on improving blade erosion resistance, an accelerated erosion experimental method was designed in this work. Five different processes were proposed, including UT, LSP, UT-HVOF, LSP-HVOF, and HVOF-LSP. The results indicate that compared with UT specimens, LSP treatment induces high compressive residual stress in the surface layer of 1Cr12Ni3Mo2VN stainless steel, which leads to shallower compound erosion pits. Compared with UT-HVOF and LSP-HVOF specimens, the HVOF-LSP specimen has the lowest coating porosity and the highest surface microhardness of 1500 HV0.5, representing an increase of 14.5% and 8.7% respectively. This demonstrates that LSP post-treatment can enhance the load-bearing capacity of HVOF coatings effectively. Microstructural analysis further reveals that the HVOF-LSP specimen presents the shallowest erosion pits and the longest penetration lifetime of the WC coating. Accordingly, the HVOF-LSP treatment can effectively improve the service life and protection performance of materials under accelerated erosion conditions, providing a technical reference for the long-term service of turbine blades.
Le et al. (Mon,) studied this question.