A Thermal Spraying Method for Slab Continuous Casting Chamfer Mold Narrow Surface Copper Plate

Abstract

The invention discloses a thermal spraying method for a narrow-side copper plate of a slab continuous casting chamfering crystallizer. Firstly, ultrasonic cleaning is performed on the surface of the narrow-side copper plate of the chamfering crystallizer, followed by a conventional electroplating method; The substrate surface of the chamfering crystallizer narrow surface copper plate is sprayed, and the PLC control system and servo motor are used to ensure that the working surface of the chamfering crystallizer narrow surface copper plate and the chamfering surface A and chamfering surface B are kept perpendicular to the spray gun during the spraying process Work; Finally, vacuum heat treatment is carried out on the surface coating of the copper plate substrate on the narrow side of the chamfering crystallizer. The process of the present invention is simple in operation, less in process and high in efficiency. The surface coating of the copper plate working surface of the chamfered crystallizer obtained has high microhardness, small internal stress and high bonding strength, and reduces the double downfall of the copper plate on the chamfered narrow surface of the crystallizer. The wear of the corner surface greatly improves the production efficiency of the continuous casting machine and prolongs the service life of the mold copper plate.

Description

technical field [0001] The invention relates to the technical field of metal surface treatment, in particular to a thermal spraying method for a narrow copper plate of a slab continuous casting chamfering crystallizer. Background technique [0002] The crystallizer copper plate is an important part of the continuous casting machine in the steelmaking plant. The copper plate includes a wide-faced copper plate and a narrow-faced copper plate, which are respectively connected to the water tank by bolts. Two wide-faced copper plates clamp two narrow-faced copper plates to form a rectangular cavity. When working, the water tank behind the copper plate circulates high-pressure cooling water. After the molten steel is injected into the rectangular cavity, the steel billet formed by cooling and crystallization is continuously pulled out from the bottom of the crystallizer. [0003] In recent years, many iron and steel enterprises in my country have continuously improved the pouring ...

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Problems solved by technology

[0003] In recent years, many iron and steel enterprises in my country have continuously improved the pouring of micro-alloyed steel in slab continuous casting production, and the narrow copper plate of the combined slab continuous casting crystallizer generally adopts a planar structure, and the corners of the slab are in a right-angle shape. However, due to two-dimensional cooling, the shrinkage of the corners is greater than the compensation for the taper of the copper plate of the mold, resulting in a large air gap at the off-angles, which affects heat conduction, accelerates the wear of the corners of the billet, and in the process of solidification of the continuous casting slab , the high-temperature brittleness of the steel along the original austenite grain boundary at the bottom of the slab vibration marks leads to transverse cracks at the corners of the continuous casting slab

In the traditional continuous casting process, the transverse cracks at the corners of the right-angle continuous casting have not been effectively controlled. In addition, during the hot rolling process, strip or fold defects are easily generated at the edge of the rolled steel plate

[0004] Some steel mills in my country have developed the slab continuous casting chamfering crystallizer copper plate technology, which effectively increases the temperature of the corner of the continuous casting slab in the straightening area, and has achieved certain results in eliminating the defects of transverse cracks in the corner of the continuous casting slab. However, This puts forward higher requirements for the surface treatment technology industry of the copper plate of the mold. Although the copper plate on the narrow side of the mold can be electroplated to increase the amount of steel passing, but the conventional electroplating layer can no longer meet the current technological status. The lower opening of the chamfered surface wears due to the sliding friction force generated by the relative movement between the cast slab and the mold copper plate when the billet is drawn, which leads to the unplanned off-line of the mold copper plate, which not only increases the labor load of replacing the mold copper plate, but also affects Improve the production efficiency of continuous casting and reduce the service life of mold copper plate

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