The uneven condensation shell in the crystallizer caused by various reasons is the main reason for the rhombus deformation. Common reasons in actual production include: crystallizer wear, deformation, and uneven inner surface; diamond-shaped deformation of the crystallizer copper tube or deflection of the assembled crystallizer copper plate during installation; uneven cooling due to scale; The injection flow deflection and local erosion of the solidification shell caused by the deflection of the nozzle installation or the misalignment of the immersed nozzle. The uneven secondary cooling aggravates the rhombus deformation. Factors causing uneven secondary cooling include: blockage of individual nozzles; misalignment of nozzle installation; uneven water volume on the four sides; excessive spray angle of the nozzle, resulting in overcooling of the corners; and excessive distance between foot rollers, which prevents crystallization. Make appropriate corrections to the billet at the bottom of the device.