The casting coating is improved and adjusted on the basis of the traditional casting coating

Resin sand coating advantages

The casting coating is improved and adjusted on the basis of the traditional casting coating, which can prevent the oxidation of the high-temperature liquid metal, and no chemical reaction occurs during the contact between the casting mold and the high-temperature liquid metal. And can absorb and digest nitrogen, sulfur, carbon and other gases.

So as to solve: casting sticky sand, trachoma, roughness, pores, inclusions (slag), ball milled iron deterioration, cast steel vulcanization cracks, carburizing defects, etc.

The main products are: gray iron castings, ductile iron castings, heat-resistant castings, alloy castings and so on.

Principle analysis of casting defects such as sand sticking, pores and sand holes

Castings stick to sand because the coating doesn’t act as a barrier or isolation, or the coating reacts chemically with the hot metal liquid.

1. Poor paint adhesion: When the sand is filled and vibrated, the paint peels off, causing the casting to stick to sand.

2. The expansion coefficient of the coating is large: when the coating is in contact with the high-temperature molten metal, the volume of the coating expands and leaves the mold, causing the casting to stick to sand.

3. The high-temperature liquid metal is oxidized and chemically reacts with the coating and the mold to form metal oxides, which have adhesion to the coating and the molding sand, and can firmly attach the molding sand to the surface of the casting to form a series of low-melting compounds [ In the thick walls and corners of the casting, there are many low-melting substances, after the sticky sand layer), which causes the casting to stick to the sand.

Casting trachoma:

1. Sand falls into the mold.

2. The coating has low strength and poor refractoriness, and cannot withstand the erosion of high-temperature molten metal. There is molding sand in the casting.

Casting porosity: There are many reasons, the common one is that there is a large amount of gas in the casting mold, which produces gas, the gas permeability of paint or sand is poor, and the gas is not removed in time.

Leave a Reply

Your email address will not be published. Required fields are marked *