Induction Melting Furnace Articles

Induction Melting Furnace in Steel Manufacturing

Steel are used for making various types of induction furnace. The induction furnace popularly used for making steel are medium frequency and high frequency. The steel that can be manufactured by using these type of furnaces are Mild Steel, Stainless Steel and low and high alloy Steel. Other raw material required for making steel are melting Scrap, direct Reduced Iron, alloying elements added as per requirement.

Modernization has been carried out by using refining, equipment as well as continuous casting of billets. Nowadays, LRF adle refining furnaces and AOD refining vessels are in use and for manufacture of stainless steel. For this it will be better to use pedigree chemical composition, medium and heavy steel melting scrap.

The technology of using DRI to adjust chemistry has been mastered. Earlier production of Direct Reduced Iron (DRI), was difficult to control chemistry of melt. Carbon can be adjusted as per specification and tramp elements are controlled because DRI does not have tramp metals and elements.

The bulk of structural quality mild steel for long products is manufactured by Induction Melting Furnaces. Nowadays Induction Melting Furnaces are also used for making mild steel. There are several reasons for growing popularity of Induction Melting Furnaces for making steel. As compared to EAFs they consume less power.

Expenditure on electrode is minimum. Quantity of refractory used by them is quite low. Investment on plant and equipment initially is less. Thus, there are economic advantages in making steel through Induction Furnaces route. The only snag is that at present bulk quantity steel cannot be produced through Induction Furnace route. May be that in future it may be possible to do so.

In emerging trend especially in India the technology used is using Direct Reduced Iron (DRl) - Induction Melting Furnaces (large capacity) Continuous Casting of Billets or Rolling Mills to Make Billets and Bars, Fods and Sections.

Chemical analysis of all input metallic is taken before shaking the charge-mix in order to control chemistry of end product. After the chemical is analyzed further additions are made of input metallics. If it has high carbon, sulphur and phosphorous, percentage sponge iron in the charge is increased. After the completion of 80% melting, final bath sample is taken. If carbon is still high, more of sponge iron fines are charged. In case carbon is less, cast iron scrap and turnings are charged. Thus, the chemistry is controlled. Due to the absence of vigorous arcing the oxidation of iron is much less and losses are also minimal.

At present Low alloy steels are regularly produced by Induction Furnace Units. Chemical composition is strictly controlled by using spectrometer.

Induction Melting Furnace before making Mild Steel has started to produce stainless steel. The raw material is purged with liquid metal in ladle, in which alloys and liquid element is added later on. The mild steel scrap is melted and ferro alloy is added. The liquid metal is transferred to AOD vessels for refining.

After AOD treatment units are further refined. All units having ladle refining system have installed spectrometer for accurate and quicker bath analysis. Most of the Induction Furnaces units are producing utensils grade stainless steel. Two induction furnaces units making SS have exported bars rods and wires. More and more Induction Furnace units are modernizing as well as diversifying to value added products.

There are many cast iron casting foundries which have installed mains frequency Induction Furnaces to make special cast irons. There are some industries which have installed medium frequency Induction furnaces to make S.G. Iron. These foundries have chemical testing, sand testing and physical testing equipment along with ultrasonic testing equipments.