Creep resistant molding sand and preparation method thereof

Abstract

The invention relates to a creep resistant molding sand. The creep resistant molding sand is prepared from the following raw materials in part by weight: 72-78 parts of quartz glass, 8-10 parts of cristobalite, 4-6 parts of zirconium oxide, 0.3-0.5 parts of calcium sulfite, 4-6 parts of rare earth tailing, 1-1.5 parts of mullite whisker, 2-3 parts of papermaking waste residue, 2-3 parts of bentonite, 4-5 parts of modified pulverized coal, 0.1-0.2 part of sodium carbonate, 2-3 parts of active calcium silicate, 0.2-0.4 part of sodium fluoride and 6.5-7.5 parts of water. According to the creep resistant molding sand, quartz glass is used as a base material and has good heat resistance and good mobility; the cristobalite is added to improve the high-temperature creep resistance of the molding sand and the size stability and the precision of a casting part; the papermaking waste residue is added to prevent the molding sand from cracking; calcium sulfite is added to achieve the reducibility and prevent the casting part from oxidization; and the modified pulverized coal has more volatile components, low ash content, uniform particles, and good mobility, and therefore, the brightness of the casting part can be improved, 10-13% of defects such as air holes and sand inclusions can be reduced and the collapsibility is improved.

Description

technical field [0001] The invention relates to the field of casting, in particular to a creep-resistant molding sand and a preparation method thereof. Background technique [0002] The so-called clay green sand for casting refers to the mixture that is mixed with raw sand, binder and attachment in a certain proportion and meets the molding requirements after mixing. Because the materials used in clay green sand casting are cheap and easy to obtain, the casting mold is simple and convenient, and it can adapt to single-piece production and batch mass production of castings. It has been the basic process of casting production for a long time. [0003] Molding sand must have the following characteristics: 1. Good air permeability. After the high-temperature metallic cast iron liquid is poured into the mold, the gas generated must be able to be discharged from the mold smoothly; 2. Good strength, to ensure that the molding sand must have sufficient strength and Concession; 3. G...

AI Technical Summary

Problems solved by technology

[0004] Existing castings have many problems, such as sand swelling, sand washing, sand loss, extravasation, pores, pinholes, shrinkage, shrinkage, porosity, cracks, sand inclusions and scarring, sticky sand, rough surface, wrinkles Skin, shrinkage and other phenomena, which have a great relationship with the molding sand, it is necessary to continuously improve the performance of the molding sand, which can be improved from the raw materials and sand mixing process