A kind of coated sand of cold iron for steel castings and its preparation method

Abstract

The invention discloses pre-coated sand of cold iron for a steel casting and a preparation method of the pre-coated sand. The pre-coated sand is prepared from the following raw materials: chromite sand, phenolic resin, a curing agent, a lubricant and a coupling agent. The pre-coated sand of the cold iron for the steel casting, disclosed by the invention, is used for accelerating the cooling of thecasting and has a chilling effect; the surface of the cold iron with the pre-coated sand prepared by the invention has high smooth finish and the pre-coated sand can be directly used for the cold iron; surface oxidization is not caused, the slag hole defect of the casting is avoided and dip coating of coating is reduced; the defect that water in the coating is not completely removed so that the casting has gas pores is avoided; the cold iron for the steel casting is collapsed at high temperature and is not stuck with the casting.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to a chilled iron-coated sand for steel castings and a preparation method thereof. Background technique [0002] Chill iron refers to the chiller placed inside the cavity and the surface area of ​​the mold in order to speed up the local cooling rate of the casting. The chill iron is used in conjunction with the gating system and the riser system to control the solidification sequence of the casting to obtain qualified castings , chilled iron is divided into inner chilled iron and outer chilled iron. The chilled iron placed on the surface of the shape during modeling is collectively called outer chilled iron; The shape of the casting is generally designed or selected according to the shape of the casting to be chilled. The metal object that is placed in the cavity and can be fused with the casting is called the inner cooling iron. The inner cooling iron is usually used w...

AI Technical Summary

Problems solved by technology

The main material of the external chill iron used in steel castings is gray iron and other metal materials, but these materials cause defects such as slag holes on the castings due to surface oxidation, and need to be repaired, smoothed, and painted with paint, and the paint may contain paint moisture. Unclean treatment causes casting porosity defects, and the existence of these defects also reduces the yield of steel castings

Existing chills for steel castings are mainly gray cast iron, and cast iron chills require machining due to surface roughness, which increases processing costs, and cast iron chills are prone to slag holes in castings because of the surface’s easy oxidation. Therefore, paint should be added to the surface of the chilled iron of cast iron to avoid the oxidation of the chilled iron and the sticking of the chilled iron and the casting. However, if the moisture in the paint is not removed cleanly, it will cause defects such as pores in the casting.