Method for preventing knots of castings in lost foam casting process

Abstract

The invention belongs to a lost foam casting process technology, specifically discloses a method for preventing knots of castings in a lost foam casting process. The method is characterized in by comprising the following steps of: mixing a silica sol and a refractory powder according to a mass ratio of 1:1-2, and stirring the mixture uniformly; uniformly spreading the prepared coating on a position where the knots can be easily formed and a common coating is applied, baking a die piece coated with the silica sol coating to dry at 45-55 DEG C, and burying a cast box after the coating on the position to be coated is dry. The method belongs to the lost foam casting process, is simple and convenient to operate and low in cost, and can obviously solve the problem of the knots in the lost foam casting process and improve product quality and product yield, thereby being suitable for all lost foam casting manufactures.

Description

technical field [0001] The invention belongs to the technology of lost foam casting, in particular to a method for preventing knots of castings in the lost foam casting process. Background technique [0002] At present, the lost foam casting technology, which enjoys the reputation of green casting, is developing very fast in our country. Many traditional foundry companies are using lost foam casting technology as a technological transformation innovation, using lost foam casting technology to produce various lost foam parts with complex structures. There are more and more manufacturers. However, castings with complex structures are prone to knot defects during the production process. For example, various gearbox body castings have some dead angles, grooves, and cavities in the part structure. During the pouring process, it is easy for the molten iron to break through the coating and contact the molding sand to form iron-clad sand. Since most of the domestic vibrating tables...

AI Technical Summary

Problems solved by technology

However, castings with complex structures are prone to knot defects during the production process. For example, various gearbox body castings have some dead angles, grooves, and cavities in the part structure. During the pouring process, it is easy for the molten iron to break through the coating and contact the molding sand to form iron-clad sand. Because most of the domestic vibrating tables are not well filled during sand filling molding, nodules (also called iron-clad sand) defects are easily generated in these parts.