Preparation method of high temperature-resistant molten metal etching composite coating

Abstract

The invention provides a preparation method of a high temperature-resistant molten metal etching composite coating. The preparation method comprises the following steps that (1) degreasing, dehumidification and sand blasting roughening pretreatment is carried out on the surface of a workpiece substrate; (2) CoCrWSi alloy powder is sprayed on the surface of the substrate through supersonic spraying, and a priming layer is formed; (3) mixed powder is sprayed on the surface of the priming layer through plasma spraying, and a transition layer is formed, wherein the mixed powder is a mixture of CoCrWSi alloy powder and compound ZrO2 ceramic powder; and (4) compound ZrO2 ceramic powder is sprayed on the surface of the transition layer through plasma spraying, and a working layer is formed. According to the preparation method, a surface gradient protective layer of which the expansion property is matched with that of a roller base material, the bonding property is excellent, stress crack andpeeling resistance is high, and aluminium and zinc melt corrosion resistance is excellent can be obtained.

Description

technical field [0001] The invention belongs to the field of material coating, and the invention relates to a surface composite protective coating and a manufacturing method thereof, in particular to a surface protective thermal coating which can be used (but not limited to) for sinking rolls and stabilizing rolls in a continuous hot-dip aluminum-silicon production line. Spray coating and method for its manufacture. Background technique [0002] At present, most anti-corrosion steel products in the world need to be hot-dip galvanized. Hot-dip galvanizing technology has become the most economical and effective method for steel anti-corrosion. Hot-dip galvanized sheet has good corrosion resistance, good processing formability, Weldability, paintability and environmental protection are widely used in various fields such as construction, home appliances, vehicles and ships, container manufacturing, and electromechanical. [0003] In the continuous hot-dip galvanizing production...

AI Technical Summary

Problems solved by technology

However, since the temperature of the molten high-alumina-silicon liquid is as high as 680-700°C, which is 200-250°C higher than that of ordinary hot-dip pure zinc (about 450°C), it is more corrosive. Traditionally used WC-Co, Thermal spray coatings such as WC-Co-Cr and Fe-Al can no longer effectively resist the corrosion of zinc-aluminum solution, and the service life of the sinking roller will be greatly reduced

Therefore, the short service life of sinking rolls and stabilizing rolls has become a bottleneck factor restricting the efficient production of hot-dip aluminum-silicon plates

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