Induction Heating for the Steel Industry

Induction technologies offer a cleaner solution to your heating needs when compared to alternate heating methods – like combustion furnaces which many rolling mills use today.  Additionally, induction systems offer a better return on your investment, lower operating costs, higher quality end products and reduced metal losses and toxic emissions.  These systems are already beginning to change the landscape of the steel industry and are a great part of the solution to decarbonizing the steel rolling process.

Providing the rolling mill with a continuous supply of uniformly heated steel slabs, billets, bars and blooms at the proper temperature is crucial to efficient mill operations. Our induction heating systems for bars, blooms, billets, plate, strip and slabs are used prior to rolling operations. Temperature control and consistency are maintained from the surface to the core and over the length of the product.

Induction heaters can be used alone or in conjunction with combustion furnaces – on green field projects or brown field projects.

Slab, Bloom and Transfer Bar Heaters

Basic Benefits of Induction Heaters for Rolling Mills:

  • Higher production flexibility.
  • Higher quality products.
  • Lower operating costs.
  • Reduced carbon emissions.
  • Reduced metal losses.


Induction heaters can also help you decarbonize by reducing CO2, SO2, NOX and other toxic emissions by at least 50%.

In a combustion furnace, heat is created by burning a fuel such as coke, oil or natural gas. The burning fuel heats up the inside of the furnace.  This then heats up the surface of the product inside the furnace. The time required to heat the workpiece is determined by the thermal conductivity of the material.

Induction furnaces heat without burning fuel.  Heat is generated on the surface of the product itself by the flow of an electrical current.

That doesn’t mean you have to completely replace your combustion furnaces. In fact, when induction heaters are used in conjunction with traditional combustion furnaces, your mill can reduce toxic emissions by 50% or more as well as increase production, improve quality, decrease operating costs and extend the life of your combustion furnaces.

A smart steel mill will look at both options to determine the optimal solution for their process.

Additional Benefits of Induction Heaters for Rolling Mills:

  • Temperature homogeneity for continuously cast products.
  • Modular design to meet any layout requirement.
  • Level control to centralize all bar sizes in coil opening.
  • High-efficiency, state-of-the-art power supplies in a range of frequencies covering all heating applications.
  • Close-coupled, high-efficiency independently controlled induction heating stations.
  • Fully-automated level 1 and level 2 controls.

Inductotherm’s IMZ™ (Induction Multi Zone) Re-heater technology

The best opportunity for mills is to replace or integrate existing combustion furnaces with new induction systems—like Inductotherm’s IMZ™ (Induction Multi Zone) re-heater technology.

Inductotherm’s IMZ™ multi-zone technology takes induction furnaces to the next level. With several coil zones, each individual heating zone can be controlled to provide any desired temperature profile along the workpiece to meet the specific requirements of the rolling mill. 

Utilizing induction technology from Inductotherm can deliver immediate benefits to rolling mills by significantly boosting their annual production of quality rolled products at a lower operating cost and with lower emissions.

For green field projects, the mill builder has multiple options in the configuration of the equipment layout. Induction furnaces can be placed in-between the Continuous Casting Machine(CCM) and the Rolling Mill (RM), upstream the rolling mill or in-between rolling stands.

For brown field projects there are several solutions available using the IMZ ™ modular design. For example, the IMZ™ induction re-heater can be placed between the CCM and the RM or in-between rolling stands when induction reheating is required by the rolling process. Another option for existing “brown field” RMs is to install an IMZ™ induction heater upstream of the combustion furnace to partially heat cold stock prior to homogenizing to the rolling temperature in the combustion furnace.