Application of chromite sand in large steel castings
1、 Prevent sand adhesion on the surface of castings
Chromite sand has excellent impermeability and solid-state sintering characteristics. When in contact with molten metal, it can prevent the infiltration of molten metal, prevent sand adhesion on the surface of castings, maintain the smoothness of the surface of cast steel parts, and thus improve the quality of castings.
2、 Improve the fire resistance of castings
The casting coating has good fire resistance and protects the mold and core during the process of melting metal. Chromium ore sand has a high refractoriness (usually greater than 1900 ° C). Grinding it into powder and adding it as refractory aggregate to casting coatings can significantly improve the refractory performance of the coatings, making them less prone to erosion, softening, or detachment at high temperatures, thereby ensuring the integrity of the mold and core, and further improving the refractory performance of castings.
3、 Accelerate the cooling rate of castings
Chromite sand is suitable for casting, such as sand casting, shell casting, and lost foam casting. When shaping (core making), placing chromite sand as a chilling material in a specific location can act as an external cooling iron, promoting the solidification of the casting in the predetermined direction, refining the grain structure, and improving the mechanical properties of the casting. Meanwhile, accelerated cooling can also reduce the tendency of hot cracking in castings and improve their crack resistance.
4、 Cooperate with multiple casting processes
In sand casting, chromite sand can be used as a component of the molding sand to improve its strength and stability; In shell casting, chromite sand can be used as the core sand material to produce high-precision, smooth surface sand cores; In lost foam casting, selecting appropriate sized chromite sand can prevent defects such as sand inclusion and sticking caused by quartz sand casting.
5、 Improve the internal tightness and strength of castings
When sand casting of chromite sand is combined with other processes, the castings can be cooled in a predetermined order..then This cooling method is beneficial for improving the tightness and strength inside the casting, making it more stable and reliable when subjected to external forces. At the same time, chrome ore sand can also reduce internal defects such as shrinkage and porosity in castings, improving the overall quality of castings.
In summary, the application of chromite sand in large steel castings has significant advantages and wide applicability. By reasonable selection and application, the quality and performance of castings can be significantly improved, meeting various complex and demanding casting requirements.