Chromite sand AFS70-80 for steel casting core making
Chromite sand AFS70-80 is suitable as a core sand material for casting cores. Chromite sand is a refractory and casting material with high sintering temperature, chemical inertness, excellent thermal conductivity, and low thermal expansion. Foundry chromite sand AFS 70-80 is mainly used for core sand in the sand prone parts of steel castings and high manganese steel castings, as well as for coating sand in alloy steel castings with high pouring temperatures.
Chromite sand AFS70-80 for steel casting core making characteristics:
- High melting point, high sintering temperature
- Excellent thermal and chemical stability
- High density, high density –
- Medium Mohs hardness 5.5
- Strong thermal conductivity
- Low coefficient of thermal expansion
Technical Index of Chromite sand AFS70-80 for steel casting core making:
- Chemicals
| Content | Guarantee Value | Typical Value |
| Cr2O3 | ≥ 46% | 46.43% |
| SiO2 | ≤ 1.0% | 0.62 |
| FeO | ≤ 26.5% | 25.62% |
| Cr：Fe | ≥1.5：1 | 1.58 |
| MgO | ≤ 10% | 9.56% |
| CaO | ≤ 0.3% | 0.2% |
| Al2O3 | ≤ 15.5% | 15.26% |
| MnO | ≤ 0.5% | 0.21% |
| TiO2 | ≤ 1.0% | 0.62% |
| P | ≤30 ppm | ≤30 ppm |
| S | ≤30 ppm | ≤30 ppm |
| L.O.I | ≤0.5% | / |
- Physical index:
| Formula | (Fe,Mg) Cr2O4 |
| CAS No. | 1308-38-9 (for Cr2O3) |
| EINECS-No. | 2151609 (for Cr2O3) |
| Mohs Hardness | 5.5-6 |
| Melting Point | 2180 ℃ |
| Sintering Point | ＞1800℃ |
| Specific Gravity | 4.0-4.8 g/cm3 |
| Bulk Density (LPD) | 2.5-3 g/cm3 |
| Color | Black |
| PH Value | 7-9 |
| Thermal conductivity | 0.63 W/M·K |
| Thermal Expansion Rate（1000℃） | 0.6% |
| Acid Demand Value (ADV) | PH3:≤ 3ML PH4: ≤ 2ML PH5: ≤ 2ML |
| Turbidity(NTU) | ≤ 200 |
| Soil content | ≤0.1% |
| Moisture | ≤0.1% |
Particle distribution of Chromite sand AFS70-80 for steel casting core making：
| Sieve Mesh | Residue Percentage |
| +50mesh(300um) | 1.19% |
| +70mesh(212um) | 32.60% |
| +100mesh(150um) | 45.60% |
| +140mesh(106um) | 15.10% |
| +200mesh(75um) | 4.10% |
| +270mesh(53um) | 1.41% |
| Grain Fineness(GFN) | AFS 72.36 |
Applications of Chromite sand AFS70-80 for steel casting core making:
- Large scale thick walled casting: Chromite sand combined with sand casting, furan resin self hardening sand, water glass self hardening sand and other processes are used for large volume and weight cast iron and steel castings. It can cool the castings in a predetermined order, which is conducive to improving the internal tightness of the castings and enhancing their strength. In addition, for the process of using silica sand, chrome ore sand can be used as surface sand instead of silica sand in key areas where porosity and veins are prone to occur, which can effectively prevent casting defects such as cracks and porosity.
- Lost foam casting. In lost foam casting, using chrome sand can prevent defects such as sand inclusion and sticking caused by quartz sand casting. Used for manufacturing castings such as valves and impellers made of high chromium cast steel and high manganese steel materials.
- Shell casting: Chromite sand can be used as a core sand material for complex components in shell casting, making sand cores. Used for producing high-precision, smooth surface 304316 stainless steel castings and carbon steel precision castings. It can effectively prevent the problem of sand sticking in the inner cavity of castings.
- Sand casting: Chromite sand can also be used for sand casting, such as sand casting, water glass self hardening sand casting, etc., to produce various large, medium, and small parts, such as pump bodies, pipelines, valves, etc.
- Resin Coated sand: Fine grained chromite sand can be used as the material for sand cores in resin coated sand casting.
Production of Chromite sand AFS70-80 for steel casting core making:
Package of Molding sand Chromite sand AFS40-50 AFS40/50:
Latest News:
Chromite sand AFS 40-50 properties and technical Index
Reviews
There are no reviews yet.