Research on laser repair technology for surface defects of flywheel disc steel plate

Abstract

Flywheel disc steel plate, used in the rear end of the engine disc-shaped parts, is one of the important components that make up the engine. However, during the manufacturing process, its surface is prone to defects such as scratches and dents. The defects position of the steel plate will produce the phenomenon of stress concentration, which directly leads to its scrapping. To solve this problem, a laser repair method is proposed, which uses laser with high energy density to repair surface defects. Firstly, the repairable defect depth under different laser parameters is predicted by finite element simulation. The temperature of the steel plates increases with the increase of the laser power density and decreases with the increase of the scanning speed. When the laser power density is 5.57×10^11 W/m^2 and the scanning speed is 120 mm/s, surface defects of various depths can be repaired, and the size of the melt pool is moderate. Then, process experiments were conducted, and the results showed that good repair effects can be achieved when the laser power is 14 W, the repetition frequency is 130 kHz, the scanning speed is 120 mm/s, and the scanning spacing is 0.02 mm. Finally, the surface with original surface roughness of 2.370 μm can be repaired by laser to obtain a flawless smooth surface with surface roughness of 0.731 μm, which provides an effective method for enterprises to repair flywheel disc steel plates.