What are the methods and measures to reduce and overcome the defects of casting slag inclusion?

The problem of sand entry and slag inclusion defects are a major problem in the production of lost foam casting. I have told you last time what are the reasons for slag inclusion in lost foam casting? Currently, the three types of products that are very successful in lost foam casting production are: Wear-resistant parts, pipe parts and box castings are all castings with little or no processing. For castings that have many machining surfaces and are going north, slag inclusion defects are a key problem to be solved. Taking measures from the following aspects can reduce and eliminate slag inclusion defects.

1. Coating

The function of lost foam coating is:

(1) Improve the surface finish of castings, reduce the roughness of castings by 2 to 3 grades, and improve the surface quality and performance of castings.

(2) Reduce and prevent sand sticking and sand hole defects.

(3) Conducive to clearing sand and falling sand.

(4) The liquid and gas melted in the lost foam during casting are discharged to the casting sand through the coating layer, and the metal liquid is prevented from being involved in the sand mold, preventing the casting from producing pores, metal penetration and carbon defects.

(5) Improve the strength and rigidity of the model, prevent deformation and damage during transportation, sand filling and vibration molding, and help improve the dimensional accuracy and yield of castings.

To prevent the defects of slag inclusion, the material should firstly have high strength and fire resistance. It is required that the coating layer applied on the surface of the white mold does not generate cracks and cracks during drying and transportation, that is, the coating should have sufficient room wet strength;