A method for testing the sintering resistance of coated sand for steel castings

Abstract

The invention relates to cast steel piece precoated sand. The cast steel piece precoated sand is mainly prepared from the following raw materials, by weight, 900-1100 parts of quartz silica sand, 45-165 parts of iron ore sand, 5-10 parts of zeolite powder, 3-8 parts of graphite powder, 1-3 parts of phenolic resin, 1-2 parts of a silane coupling agent, 0.1-0.6 parts of an urotropine hydrochloride solution and 0.9-5.5 parts of calcium stearate. According to the cast steel piece precoated sand and the preparation method thereof, the cast steel piece precoated sand is low in production cost, whichis only 25-30% of the production cost of the special cast steel piece precoated sand added with the pagoda sand; the cast steel piece precoated sand has the advantages of being high in heat resistance, good in low expansion performance, good in scouring force of the high-temperature-resistant molten steel and high in anti-sintering property, the gas releasing speed of a sand core is delayed, gasreleased by the sand core can be absorbed, and the cast steel piece precoated sand is suitable for production and use of a thick-large cast steel; the cast steel piece produced by using the precoatedsand is high in surface smoothness, the cast steel piece can be used without machining or with slightly processing, so that the yield of the cast steel piece is greatly improved, and the cast steel piece has high economic and social values; and the anti-sintering property detection method thereof has the advantages of being convenient in operation, the anti-sintering performance of a product is compared in the transverse direction, the result is scientific and reasonable, and data reference value is high.

Description

technical field [0001] The invention belongs to the technical field of foundry industry, and in particular relates to coated sand for steel castings, a preparation method thereof and a detection method for sintering resistance. Background technique [0002] Cast steel is stronger than ordinary cast iron, has many advantages such as strong fatigue resistance and long service life against corrosion. In China, the use of high-performance cast steel parts is becoming more and more extensive, and the quality requirements of cast steel are also increasing. higher. During the casting process of steel castings, because of the high melting point of cast steel, the corresponding pouring temperature is also high, reaching 1500-1100 ° C, which is close to the refractoriness of quartz sand. Molten steel is very sensitive to gas at high temperature, and will also react chemically with casting materials, and castings are prone to defects such as sintering sand sticking and pores. [0003...

AI Technical Summary

Problems solved by technology

[0005] When the casting is poured, the temperature is generally 1400-1100 °C, and the low melting point substance in the silica sand will chemically react with the molten metal, so that the surface of the casting and the sand are sintered and melted together, resulting in the scrap of the casting. Therefore, coated sand for steel castings is used in formal Before it is used in steel castings, the detection of its anti-sintering performance is particularly important, but at present there is no relevant detection method or standard in China to measure the high-temperature sintering performance of coated sand

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