The role of cryolite in casting

Cryolite is a widely used chemical product, generally used for electrolytic aluminum, can also be used in the casting industry. Many people do not understand the use of cryolite in the casting industry, today we will understand together. Cryolite is mostly used in the production of ductile iron, cryolite does not react to water.

1, Sprinkle on the surface of liquid iron, the amount of 0.1%-0.3%. For slag removal and covering, cryolite can dilute the slag, making it easy to collect and remove. Cryolite is decomposed by heat (greater than 1011℃) to produce AlF3 gas. It can protect the surface of liquid iron and prevent oxidation, but this gas is harmful to people.

2. The surface of the wet cavity is covered with cryolite powder to effectively prevent subdermal pores. After pouring, there is a cryolite solution layer at the metal-cast interface, which can dissolve the water on the interface and reduce the things generated by the reduction reaction, reducing the base required for hydrogen precipitation to form bubble core in the interfacial liquid iron layer. At high temperature, the AlF3 gas generated by the decomposition of cryolite can protect the chemical reaction of different interfacial water gases in the liquid iron layer and prevent the hydrogen absorption of the liquid iron layer.

3, if you do not use crorite, spherodizing treatment due to the slag viscosity, slag removal is difficult, slag removal is not clean, so that the casting formation of slag inclusion defects significantly increased, but also many times the phenomenon of spherodization decline, analysis that: this is not the bottom of the slag has a direct relationship because Mgs and ce-2s-3 in the slag and oxygen in the air reaction. From many years of production practice, cryolite has played a certain role in reducing porosity, slag inclusion and spheroidization decline.