Casting moulding sand high in sand discharging performance and wet stickiness

Abstract

The invention discloses casting moulding sand high in sand discharging performance and wet stickiness. The casting moulding sand is prepared from, by weight, 40-60 parts of quartz sand, 20-30 parts of dead-burned magnesia, 5-10 parts of silica powder, 20-30 parts of gypsum powder, 10-20 parts of kaolin, 30-50 parts of clay, 10-20 parts of pulverized coal, 3-8 parts of graphite powder, 1-8 parts of sodium carbonate, 2-6 parts of lignin fibers and 10-20 parts of water. The raw materials low in expansion coefficient and the raw materials low in stickiness and good in air permeability are mixed, and therefore the casting moulding sand is low in shrinking rate; excellent sand sticking prevention capacity is achieved, and the sand discharging performance between the moulding sand and a casting is good; and meanwhile wet stickiness during preliminary machining is good, and therefore the yield and machining efficiency of casting machining are increased.

Description

technical field [0001] The invention relates to the technical field of molding sand for casting, in particular to molding sand for casting with high sandability and wet viscosity. Background technique [0002] The role of molding sand in foundry production is extremely important. The casting waste caused by poor quality of molding sand accounts for about 30-50% of the total casting waste. Foundry production generally requires molding sand to have high strength and thermal stability to withstand various external forces and high temperatures; good fluidity, that is, the ability of molding sand to move between sand particles under the action of external force or its own gravity; Certain plasticity, that is, the ability of the molding sand to deform under the action of external force, and maintain the given shape when the external force is removed; good air permeability, that is, the ability of the pores of the molding sand to pass through gas; high sand production, also known a...

AI Technical Summary

Problems solved by technology

[0003] Various casting defects often occur in castings during the production process, such as cracks, pores, sand holes, shrinkage cavities, etc., and the generation of cracks is related to the bonding and detachment between castings and casting sand. The existing casting Molding sand is poor in sand production, and it is easy to bond with the casting, which makes the casting difficult to peel off, resulting in a rough surface of the casting, which leads to a high rejection rate of the casting; and the wet viscosity of the initial processing is poor, making the casting processing efficiency low