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.

Spinning forming is a metal plastic processing technology used to manufacture thin-walled hollow axisymmetric parts. However, during the spinning process, issues such as excessive local loads can induce non-uniform plastic deformation, leading to poor forming quality. In this study, orthogonal experiments were conducted on V-groove specimens made of SPHE steel under different ultrasonic power (with constant static load and spinning passes) and different numbers of spinning passes (with constant static load and ultrasonic power). For each parameter set, three specimens were tested, and finite element analysis using Abaqus.2021 software was performed for verification. The study explored the influence of introducing ultrasonic-assisted spinning during spinning on the forming quality of the V-groove, as well as the effects of controlling ultrasonic power and spinning passes. By combining the ultrasonic-assisted spinning experiments with finite element simulation results, the effects and relative significance of different ultrasonic power and different spinning passes on forming quality were evaluated through analyses of V-groove depth, inclination angle, microhardness, microstructure, and roughness. The results show that ultrasonic-assisted spinning significantly improves the forming depth of the V-groove. Under 50% ultrasonic power, the groove depth increased from 434.54 μm under the reference condition to 598.09 μm. Meanwhile, the groove angle decreased from 63.27° to 60.77°, indicating improvements in groove sharpness and geometric accuracy. When the spinning passes reached 54, the groove depth increased from 299.84 μm to 560.68 μm. The findings demonstrate that ultrasonic power and the spinning passes can effectively regulate the geometric morphology of the V-groove and improve the forming quality in ultrasonic-assisted spinning.