According to the test and results, the reinforced coating worked on the blades has a dense structure and no defects. The average thickness of the cladding coating is 0.45mm, and the average thickness after polishing is 0.30mm. The surface roughness is Ra0.6~1.2um. The maximum temperature measured during laser cladding operation is 130°C. During the laser processing process, the heat source is concentrated and the action time is short. Under the condition of good heat dissipation of the blade, it can ensure that the blade temperature is at a low level during operation, and the blade maintains good stiffness during the operation, thereby avoiding thermal deformation of the blade. All parameters of the coating met the requirements and passed the review of the expert group.

Improving the surface of the runner blades

In March 2018, an experimental on-site laser cladding reinforced coating construction was carried out on the No. 1 and No. 2 blades of Gezhouba Unit 8, covering a total of 8 square meters. The construction location was a cavitation-prone area. To strengthen the cavitation resistance of axial flow unit blades, welding skirts and thermal spraying WC hard materials on the blade edges are often used, which can achieve a certain effect. Thermal spraying has low bonding strength and is easy to fall off. Once the coating falls off, the corrosion resistance will be reduced. greatly weakened. A layer of cobalt-based corrosion-resistant and wear-resistant material was laser-cladded on the cavitation-prone area 400mm away from the edge of the blade. The test results showed that there were no obvious defects or deformations in the coatings of the two blades, proving that the coating prepared by laser cladding has a dense structure. The molding effect is good. According to the test and results, the reinforced coating worked on the blades has a dense structure and no defects. The average thickness of the cladding coating is 0.45mm, and the average thickness after polishing is 0.30mm. The surface roughness is Ra0.6~1.2um. The maximum temperature measured during laser cladding operation is 130°C. During the laser processing process, the heat source is concentrated and the action time is short. Under the condition of good heat dissipation of the blade, it can ensure that the blade temperature is at a low level during operation, and the blade maintains good stiffness during the operation, thereby avoiding thermal deformation of the blade. All parameters of the coating met the requirements and passed the review of the expert group.