Abstract: With the aim of studying the evolution patterns of temperature and microstructure of metal disks during the heat-treatment process subsequent to rotary forging, a finite-element analysis model for heat treatment was formulated by means of the DEFORM software. Subsequently, the reliability of the finite-element model was validated through experimental means. Based on the validated finite-element model, an analysis was carried out for the distribution and evolution of temperature and microstructure within the metal disk during the austenitization and quenching processes. The results show that during the austenitization of the metal disk, when the heating time reaches 80 s, the maximum temperature difference between the inner and outer parts is 214 ℃. When the quenching time is 2.7 s, the maximum temperature difference between the inner and outer parts is to 613 ℃. The temperature on the outer side of the disk is notably higher than that on the inner side, which makes it susceptible to the formation of non-uniform thermal stress defects. After quenching, both the inner and middle regions of the metal disk are composed of ferrite, martensite and bainite, yet the content of each microstructure varies. In the inner region, the proportions of ferrite, martensite and bainite are 58.81%, 18.64% and 22.40% respectively, while in the middle region, they are 56.46%, 22.92%, and 20.45% respectively. The outer region of the metal disk has the highest content of martensite（96.07%）, with bainite and austenite accounting for only 2.87% and 0.6% respectively. After the quenching process, the outer side and surface of the metal disk exhibit the highest hardness, whereas the hardness at the core of the inner and middle regions is relatively lower.