The last-stage blades of the steam turbine commonly face issues with water erosion, which becomes more pronounced during low-load operation of the unit. Blades affected by water erosion not only reduce the working output of the steam turbine but also pose risks to the safe operation of the unit.

Main Performance Indicators:

1. Bonding Strength: ≥ 70 MPa
2. Porosity: ≤ 1%
3. Microhardness: HV0.3 > 1250
4. Thermal Shock Test: After 80 tests, no cracks or delamination of the coating were observed under 5x magnification.
5. No Deformation: During the spraying process, the surface temperature of the workpiece will not exceed 200 degrees, and the coating will not be too thick, ensuring no impact on dynamic balance.

Solution: Using supersonic flame spraying to reinforce the surface of the blades can extend their service life, and multiple coatings can be applied. Due to the low temperature of the substrate, the original properties of the material are not damaged. The coating is relatively thin, ensuring that the blades do not deform, and the dynamic and static balance of the turbine rotor after spraying remains unaffected.