Resin self-hardening core sand for casting train iron castings and preparing method of resin self-hardening core sand

Abstract

The invention discloses a resin self-hardening core sand for casting train iron castings and a preparing method of the resin self-hardening core sand. The resin self-hardening core sand is prepared from, by weight, 160-180 parts of sea sand, 20-30 parts of carborundum, 16-20 parts of refiring magnesia, 10-14 parts of paper clay, 6-8 parts of chalk soil, 10-15 parts of furan resin, 12-14 parts of cashew nut shell oil modified phenolic resin, 4-6 parts of polyimide, 3-5 parts of rare earth tailing, 5-7 parts of pandermite, 8-10 parts of waste foam glass, 3-5 parts of ferro silicon nitride, 1-2 parts of N-(beta-aminoethyl)-gamma-aminopropyl triethoxy silane, 2-4 parts of p-toluenesulfonic acid, 3-5 parts of phosphoric acid, 4-6 parts of castor oil maleic anhydride acid esters, 8-10 parts of triphenylmethane triisocyanate and 2-4 parts of styrene. According to the furan resin self-hardening sand, mixed resin is adopted, the method of adding single resin is changed, mutual effects between different kinds of resin including the furan resin, the cashew nut shell oil modified phenolic resin, the polyimide and the like are adopted for enabling the core sand to have the beneficial effects of being high in strength, small in gas-forming amount, low in thermal expansivity, good in breathability, good in collapsibility and the like, and the produced castings are high in degree of precision and good in surface quality.

Description

[0001] field of invention [0002] The invention belongs to the field of foundry industry, and in particular relates to a resin self-hardening core sand used for casting iron castings of trains and a preparation method thereof. Background technique [0003] Core sand is the material used to cast the core in the casting process. It is generally made by mixing molding materials such as casting raw sand, molding sand binder and auxiliary additives in a certain proportion. Clay and water glass are widely used as molding sand binders. Clay is the most widely used and the largest amount of molding sand binder. However, sodium silicate sand has become one of the fastest-growing types of molding sand in recent decades due to its high fluidity, high compaction rate, fast hardening, high casting precision, wide source, low price, and environmental protection. At present, most iron castings are produced by the water glass sand process. Although the water glass sand has many advantages,...

AI Technical Summary

Problems solved by technology

However, there are also shortcomings. Resin self-setting sand is easy to expand when heated, and has a large amount of gas generation, which is easy to cause defects such as pores, hot cracks, and surface microcracks in castings.

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