Abstract：Based on the production process of 22CrMoH automobile gear steel by continuous casting and continuous rolling of 500 mm large round billet, through the analysis of low-magnification structure, high-magnification metallurgical structure and strip structure of rolled billet, the as-cast microstructure and rolling of gear steel large round billet were carried out. It was found that the dendritic size of the 22CrMoH gear steel continuous casting large round billet were significantly different in the near surface fine grain region, the columnar crystal region and the central equiaxed crystal region. The secondary dendrite spacing from the surface to the core gradually increases, and ferrite dominated the main dendritic trunk and pearlite dominated the dendrite. After rolling, the banded structure is mainly affected by the secondary dendrite spacing and rolling deformation of the as-cast microstructure, and the bandwidth of annealed ferrite increased from surface to core after rolling
2020, Vol. 39 
