① Stable melting process and high mechanical strength of castings
Induction furnaces enable stable melting of various types of cast iron. Due to minimal oxidation losses during the melting process and the ease of adjusting both chemical composition and temperature of the molten iron, the quality of the resulting melt is highly consistent. In general, replacing cupola furnaces with induction electric furnaces for cast iron melting can reduce casting scrap rates by one-third to one-half.
Cast iron produced in induction furnaces contains 1/3 to 1/4 less dissolved gases (nitrogen, hydrogen, and oxygen) and fewer non-metallic inclusions compared to that from cupola furnaces, resulting in higher strength and more reliable performance. Consequently, the cross-sectional area of cast components can often be reduced, leading to a 20%–25% reduction in metal consumption. This not only saves raw materials but also reduces the weight of machinery and equipment.
② Reduced melting loss or oxide-free melting for non-ferrous metals
When melting aluminum or aluminum alloys in induction furnaces, the absence of oxidizing flames—common in flame-fired furnaces—combined with rapid melting rates significantly reduces oxidation losses. Recent adoption of medium-frequency induction furnaces further enhances melting speed while minimizing electromagnetic stirring, thereby lowering oxidation during melting compared to conventional flame furnaces.
For copper melting, channel-type induction furnaces are particularly advantageous. Their sealed furnace chambers allow easy introduction of reducing or protective atmospheres to prevent oxidation of the molten copper. As a result, this type of induction furnace has become the standard and ideal choice for producing oxygen-free copper rods, bars, sheets, and wires.
③ Ability to utilize low-cost raw materials
The electromagnetic stirring effect inherent in induction furnace melting is especially beneficial for processing machining chips and fine scrap. When such small waste materials are added to the surface of the molten iron, they are quickly drawn into the melt and dissolved with minimal oxidation loss. These fine scraps are difficult to use directly in other types of iron-melting furnaces. The capacity of induction furnaces to efficiently incorporate large quantities of inexpensive scrap significantly lowers charge material costs.
④ Reduced environmental pollution
Induction furnaces produce no combustion byproducts since they do not rely on fuel combustion for heating. Consequently, they emit far less smoke, dust, and noise compared to cupola furnaces. This greatly improves working conditions and reduces labor intensity. Wherever feasible, using induction furnaces for both melting and holding prior to casting in cast iron production offers substantial advantages.
Moreover, after switching to induction furnaces, the increased strength of castings not only enhances equipment reliability but also allows for appropriate weight reduction in machinery. Additionally, improved wear resistance of the cast components extends the service life of the equipment.
