Application Research on Preparatory Heat Treatment Process of Marine Large-Size Gears

Setting up the preparatory heat treatment process in the part manufacturing process can effectively improve the machining performance of the part, reduce the internal stress of the workpiece and provide a good microstructure for its final heat treatment. Firstly, this paper discusses the process theory of normalizing and detects and analyzes the surface crack phenomenon of ZG310-570 marine large-size gears after heat treatment and carries out the strategy research on eliminating the surface crack phenomenon of parts after quenching and tempering. In two possible effective schemes, the preliminary heat treatment combination scheme of high-temperature normalizing + normalizing + quenching and tempering is finally adopted. After experimental verification, the surface crack problem of this batch of large-size gears after heat treatment is solved.