Double-layer refractory coating used for centrifugal casting process metal die and spraying process thereof

Abstract

The invention relates to a double-layer refractory coating used for a centrifugal casting process metal die. The double-layer refractory coating used for the centrifugal casting process metal die is characterized by comprising a bottom-layer refractory coating body and a surface-layer refractory coating body; the bottom-layer refractory coating body comprises, by mass, 40%-50% of graphite powder, 9%-11% of a binder and 50%-40% of water; and the surface-layer refractory coating body comprises, by mass, 40%-50% of mullite powder, 9%-11% of a binder and 50%-40% of water. According to the double-layer refractory coating used for the centrifugal casting process metal die, the metal die coating used in the centrifugal casting process is studied, and the graphite refractory coating preparation method and the mullite refractory coating preparation method are adopted, so that not only is the problem that the two coating bodies are bonded with each other solved, but also mutual noninterference of the two coating bodies is ensured; functionally, the advantage that casting demolding is easy through the graphite refractory coating body and the advantage that the casting surface quality is ensured through the mullite refractory coating body are combined; a casting produced by centrifugal casting by using the metal die sprayed with the double-layer composite coating is easier to demold, and surface pores are decreased; and accordingly, the service life of the metal die is prolonged, and the production efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of special casting, and in particular relates to a double-layer refractory coating for a centrifugal casting process metal mold and a spraying process thereof. Background technique [0002] Centrifugal casting is an advanced casting process, and refractory coating is a key technology in the production process of metal mold centrifugal casting process. The quality of refractory coating directly affects the life of metal molds, casting quality and casting productivity. The function of the coating includes the following aspects: reduce the thermal shock suffered by the metal mold and increase its service life; prevent direct contact between the casting and the metal mold, increase the demoulding speed, and improve the productivity of the casting; adjust the thermal resistance of the system, control the cooling rate, and Ensure that the structure and performance of castings meet the requirements; ensure the sur...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the refractory coatings circulating in the market adopt the single-layer refractory coating process. Such a refractory coating process is difficult to achieve multi-functional considerations. As usual, it is difficult to demould, and surface defects such as pores and slag inclusions are prone to occur.

This more or less hinders the widespread application of the centrifugal casting process