Preparation method of composite coating for long-side copper plate of continuous casting mold

Abstract

The invention discloses a method for preparing a composite coating of a long-side copper plate of a continuous casting mold. In the method, the surface of the long-side copper plate is first pretreated to form a surface to be sprayed; the surface to be sprayed is thermally sprayed with a low-stress coating, and the low-stress coating The material is nickel-based alloy powder; then thermally spray the working coating on the part from one quarter to less than one third of the total length of the long-side copper plate at the top of the long-side copper plate, and the working coating material is based on the nickel-based alloy powder. Doping a certain amount of WC, Cr 2 C 3 Or TiC, or their mixture powder, the thickness of the working coating gradually increases from top to bottom and the transition is smooth; 2 Heat treatment under gas shielding forms a metallurgical bond between the coating and the copper substrate. The coating prepared by the method has high bonding strength with the copper plate base material body, and the copper plate is less deformed, has good thermal conductivity, high temperature corrosion and wear resistance, and significantly improves the service life of the long-side copper plate of the continuous casting mold.

Description

technical field [0001] The invention belongs to the field of material surface modification, and in particular relates to a preparation method of a composite coating of a long-side copper plate of a continuous casting mold. Background technique [0002] Continuous casting is one of the main methods of producing steel billets, and the mold is the core component of the continuous casting unit and plays a key role in continuous casting. The principle is to rapidly cool and solidify the molten metal to form a solidified shell with sufficient thickness. Avoid the phenomenon of steel running when the steel strip moves to the secondary cooling, that is, it plays the role of solidifying molten steel and forming a billet in the continuous casting production process. The performance of the mold directly or indirectly affects the quality and productivity of the continuous casting slab. The existing thermal spraying technology has well solved the three important factors of the short sid...

AI Technical Summary

Problems solved by technology

However, there are few application cases of thermal spraying technology in the long side copper plate of continuous casting crystallizer. Thermal spraying problem, but due to the large stress of a single coating, the deformation of the copper plate is serious, which affects the later on-site installation. At the same time, the corrosion resistance and thermal conductivity of the top coating on the copper plate are relatively poor, which reduces the service life of the copper plate

Another Chinese patent application (CN104759596A) discloses a long-life composite coating continuous casting crystallizer copper plate and its preparation process. It adopts the method of electroplating metal nickel on the upper part of the copper plate and thermal spraying coating on the lower part to solve the problem of the upper and lower mold copper plates. Different requirements for performance, but this method requires two processes of electroplating and thermal spraying for the copper plate. Not only is the manufacturing process complicated and the cost is high, but it is also difficult to eliminate the boundary stripes between the electroplating layer and the thermal spraying layer, and there are hidden dangers of damage, which is difficult for high-end users to accept.

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