Investment casting for engineering machinery

Investment mold precision casting process after a certain time, will produce sand, due to carbon steel precision casting surface sand is steel oxidation, traditional casting coatings only in cast iron and metal casting fully used to prevent the protective effect to ensure the purpose of slag, but sometimes in the cast iron part or large slag. Ferrous oxide is a key generator, also due to high temperature liquid metal oxidation and transformed into nickel hydroxide FeO, its melting point is 1370 ℃. FeO and type sand SiO2. chemical reaction into magnesium ferrous chloride, magnesium ferrous chloride melting point is extremely low, only 1220 ℃, therefore, very good mobility. Even if the surface of the cast iron parts of the investment casting parts have curing shell, the newly transformed ferrous magnesium chloride is still liquid, which is conducive to penetrate into the industrial coating into the sand mold porosity.

Magnesium ferrous chloride before condensation to precision casting, industrial coatings and type sand has a weak bond, can be firmly bonded to the type sand in the cast iron surface, resulting in a series of low-solution point compounds (cast iron slag, called organic chemical slag, in cast iron thick-walled steel pipes and corners, etc., more low-solution point material, sticky strong weathering more after).