Specific applications of chromite sand in the foundry industry
Chromite sand is a spinel ore containing chromium oxide, iron oxide and a small amount of silicon and calcium. After being crushed into fine particles, it is in the form of sand and is also called chrome sand or iron chromite sand. Because chromium ore has the advantages of high refractory temperature, fast heat conduction cooling speed, solid phase sintering, and low expansion coefficient, it is considered to be a good casting sand and face sand for steel castings.
Chromite sand can be used in different materials and casting processes. The specific applications range are as follows:
1. Casting of large thick-walled castings: chromite sand is used in combination with sand casting, furan resin self-hardening sand, water glass self-hardening sand and other processes for large volume and weight of cast iron and steel castings. It can make the castings cool in a predetermined order, which is conducive to improving the tightness of the castings and enhancing the strength of the castings.
In addition, for the process using silica sand, chromite sand can be used as face sand instead of silica sand in key parts where pores and veins are prone to appear, which can effectively prevent casting defects such as cracks and pores. Commonly used models are chromite sand AFS40-45 and AFS45-50 etc.
2. Lost foam casting. In lost foam casting, the selection of chromite sand AFS20-25 AFS25-30 AFS30-35 and other coarse sand can prevent defects such as sand inclusion and sand sticking caused by quartz sand casting. It is used to manufacture valves, impellers and other castings made of high chromium cast steel and high manganese steel.
3. Shell casting: Chromite sand can be used as core sand material for complex parts in shell casting to make sand cores. It is used to produce high-precision, smooth-surfaced 304, 316 stainless steel castings and carbon steel precision castings, etc., which can effectively prevent the problem of sand sticking in the inner cavity of the casting.
4. Sand casting: Chromite sand can also be used for sand casting, such as sand casting, water glass self-hardening sand casting, etc., and is used to produce various large, medium and small parts, such as pump bodies, pipes, valves, etc.
6. Casting sand filling material: Chromite sand has a good chilling effect and can be put into the sand box as a cooling material instead of cold iron. The commonly used model is chromite sand AFS20-25.
In general, chromite sand can be used in a variety of casting processes. It has a wide range of applications and can produce high-precision, high-performance, and high-strength castings. It is worth noting that chromite sand is not suitable for the production of alloy castings with low pouring temperatures.
