Extruded graphite block for exothermic welding
Technical Characteristic
As the material of exothermic welding mold, graphite has the following characteristics:
1) High temperature resistance: The melting point of graphite is 3850±50℃, and the boiling point is 4250℃. Even if burned by ultra-high temperature arc, the weight loss is very small, and the thermal expansion coefficient is also very small. The strength of graphite increases with increasing temperature. At 2000°C, the strength of graphite doubles. The temperature of the chemical reaction that ignites the exothermic flux during the exothermic welding construction is very high, so the material used in the exothermic welding mold needs to be resistant to high temperatures.
2) Electrical and thermal conductivity: The electrical conductivity of graphite is one hundred times higher than that of general non-metallic minerals. The thermal conductivity exceeds that of metal materials such as steel, iron, and lead. Thermal conductivity decreases with increasing temperature, even at extremely high temperatures, graphite becomes an insulator. Graphite can conduct electricity because each carbon atom in graphite forms only 3 covalent bonds with other carbon atoms, and each carbon atom still retains 1 free electron to transfer charge. In the exothermic welding construction, it is often necessary to weld a lot of points, and the amount of construction is not small. The thermal conductivity of graphite can meet this point, which can withstand high temperatures and can quickly cool down.
3) Lubricity determines the thoroughness of separation: The graphite block of the exothermic welding mold has a small friction coefficient and good lubricity. After the welding is completed, the separation from the welding material is very thorough.
4) Chemical stability determines use and storage life: the finished exothermic welding mold has good chemical stability at room temperature, and is resistant to acid, alkali and organic solvent corrosion.
5) Durability of exothermic welding mold: Graphite has good toughness and can be crushed into very thin flake. Exothermic welding sometimes requires exothermic welding molds of various joint forms. Easy-processing graphite can be machined into exothermic welding molds of different models, specifications, and connection forms.
Based on the above necessary characteristics of exothermic welding molds, we choose high-purity graphite to process the molds.
The ash content can be purified to 30ppm according to the requirement. / The above index data is the standard value, not the guaranteed value.
Product Size
Grade: NX82
Grain size(≤): 0.8mm
Bulk Density(≥): 1.72g/cm3
Ash (≤): 0.3%
Specific Resistance ≤8.5μΩM
Compressive Strength ≥35MPa
Flexural Strength ≥13.5MPa
Coefficient of Thermal Expansion ≤2.2×10-6/℃
Grade: NX603
Grain Size(≤): 25μm
Bulk Density(≥): 1.80g/cm3
Compressive Strength(≥): 60MPa
Flexural Strength(≥): 30MPa
Porosity(≤): 17%
Specific Resistance(≤): 12μΩm
Ash Content(≤): 600ppm
Shore Hardness: 50
Coefficient of Thermal Expansion(≤): 5×10-6/℃
Q1. Are you a factory or trading company?
A: We are an ISO9001-Qualified processing manufacturer with 70000 square meter factory area.
Q2. Can you introduce your main products?
A: Sure.
Jiangxi Ningheda New Material Co., Ltd. mainly produces graphite products, we can offer customized shape according to customers’ specific demand. Our Graphite Products, including molded graphite products, isostatic graphite products, extruded graphite products, vibration moulding graphite products. We can produce a lot of graphite products, like graphite mold, graphite casting die, graphite heating element, graphite crucible, graphite sealing ring, graphite tube, graphite rod, graphite edm, graphite block etc.
Q3.What is your MOQ?
A: 1 piece (graphite block, graphite rod, graphite box, graphite mold, graphite material, graphite seal ring, graphite crucible, graphite products, graphite sintering mold, graphite heater etc.).
Q4. Can you offer free samples?
A: Yes, usually we can offer free samples for customers to check the quality, but do not afford express charge.
However, if the sample is expensive, we have to charge basic cost of the sample. And samples delivery time is 3-10 days usually.
Q5. When can I get the price?
A: We will reply you within 24 hours after getting your detailed requirements, like size, quantity etc. If you need an urgent response, pls call us directly.
Q6. Do you accept OEM or ODM orders?
A: Yes, of course, most of our products are customized.
Q7. How about your delivery time?
A: Usually 7 to 25 days after advance payment.
Q8. Do you test your goods before delivery?
A: Yes, we have strict inspection system.
Q9. How do you keep long-term business relationship?
A: 1. Good quality and competitive price to ensure mutual benefit;
2. Quick reply and sincere service.
Remark: When you contact us, please show us the accurate drawing(s) and your selected graphite material information, then we can offer you accurate price(s).
