Abstract: Aiming at the defects of the original heat treatment process of the pin shaft for the large engine chain, the heat treatment process of the pin shaft was improved. The results show that the distortion of the pin shaft after quenching is reduced effectively, and the retained austenite content on the surface of the part is adjusted reasonably. By improving the heat treatment process, the quality of chain pin shaft is improved remarkably.

Key words: pin, distortion, retained austenite