Coated core sand for casting train steel casting and preparation method of coated core sand

Abstract

The invention discloses coated core sand for casting a train steel casting and a preparation method of the coated core sand. The coated core sand is prepared from, by weight, 170-180 parts of hill sand, 30-40 parts of zircon sand, 20-30 parts of emery, 15-20 parts of ceramsite, 15-20 parts of montmorillonite, 2-4 parts of phenolic resin, 2-3 parts of BT resin, 1-2 parts of diethoxy-methyl-[3-(oxiran-2-ylmethoxy)propyl]silane, 0.6-0.8 part of urotropine, 0.5-0.7 part of rosin pentaerythrityl ester, 5-7 parts of tephra, 6-8 parts of quartz crucible waste, 2-3 parts of salty mud, 0.3-0.5 part of paratoluensulfonyl chloride, 0.2-0.4 part of (H2NCH2C6H4)2O , 1-2 parts of trioctyl trimellitate, 3-5 parts of bismuth oxide, 4-7 parts of ferronickel slag and 20-30 parts of ethyl alcohol. The coated core sand has very high sand burning resisting capacity and veining resisting capacity, has the beneficial effects of being high in strength, small in gas generating amount, good in heat resistance and the like and is suitable for producing the steel casting, and the defects such as veining, sand burning and pores can be remarkably reduced.

Description

field of invention [0001] The invention belongs to the field of foundry industry, and in particular relates to a film-coated core sand for casting train steel castings and a preparation method thereof. Background technique [0002] Coated sand is a molding sand or core sand that is covered with a solid resin film on the surface of the sand grains before molding. There are two coating processes: cold method and hot method: the cold method dissolves the resin with ethanol, and adds urotropine during the sand mixing process, so that the two are coated on the surface of the sand, and the ethanol volatilizes to obtain coated sand; Preheat the sand to a certain temperature, add resin to melt, stir to coat the resin on the surface of the sand, add urotropine aqueous solution and lubricant, cool, crush, and sieve to obtain coated sand. Coated sand used to make sand cores has the characteristics of simple core-making process, high production efficiency, fast hardening response, smal...

AI Technical Summary

Problems solved by technology

However, there are also shortcomings, such as large gas generation, weak sand and vein resistance, poor heat resistance, etc., which will cause defects such as veins, sand sticking, and pores in the casting.

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