COMAINTEL’s Induction Roll Heating Systems Address Steel Sheet Quality and Production issues with Optimal Profile Control


Whether it is to preheat work roll (WR) or to address flatness and profile issues during Steel sheet rolling Comaintel’s Induction Roll Heating System (IRHS) were designed to meet your requirements.

In many Steel Rolling processes the firsts steel rolled coils are used to create the proper thermal and profile set-up to meet steel rolled specifications requested by the client. Therefore they are immediately recycled because they do not meet final product specifications (e.g. not the good profile and weren’t rolled under the proper mechanical properties). Comaintel’s IRHS can rapidly preheat the WR to the requested temperature and profile off or on rolling mill leading to major material, time, and energy savings.

More specifically, achieving the best possible flatness is one of the main objectives of Metal Rolling. However for most alloys, the edges of the sheet will be slightly thinner than the center (Positive Crown) usually observed at the beginning of the Rolling process and afterwards the thickness of the edges will increase due to uneven temperature distribution (Wedge Effect) caused by the nip pressure. On-production profile modification is also possible using Comaintel’s IRHS where the induction coils (controlled by small zones: 30-75 mm) will transfer the required energy to the WR to balance the nip pressure.

Rolling Mills are equipped with mechanical systems (e.g. Hydraulic Pistons) and Lubricant Systems (e.g. Zone Cooling Sprays) to try to improve Gauge Profile Control however on thin gauge sheet they have shown not to be efficient.

Over the years Comaintel’s IRHS has proven in all installation the tangible benefits it brings along with its efficiency and reliability.

Production and Operational Issues:

Even with all the existing actuators used to control the Flatness and Profile issues, the Gauge Control Systems regularly don’t address the Quality Output requirements.

Therefore causing:

  • Edge Cracking and Strip Breaks;
  • Reduce coiling speeds (to reduce Edge Cracking and Strip Breaks);
  • Premature wear of Work Rolls due to high negative bending pressure and reduced coolant spray at edges;
  • Irregular Gauges along sheet through temperature variances along Work Rolls


Induction Roll Heating is applied to the Work Rolls (WR) at the edges or all across of metal sheet to increase zoned independent WR diameter (using induction heating) to control flatness where the Actuators and Lubricant Systems can’t control sheet gauge (often required at the metal sheet edge positions). The Induction Roll Heating technology has proven to be very efficient and cost effective bringing a quick ROI. Clients are confirming mill speed increases are significant.

Based on Rolling Mill implementation of Comaintel’s Induction Roll Heating technology, it has generated many benefits:

  • Reduce Down Time with less Edge Cracking and Strip Breaks;
  • Increase Mill Speed sharply;
  • Significantly reduced Crown and Wedge Effects;
  • Reduce Bending force allowing less Work Roll wear;
  • Up to 90% Power efficiency;
  • Significant reduction in energy costs compare to conventional hot lubricant sprays;
  • xCore 6 kW 60 to 120 mm; Opticoil 6kW 30 mm and Opticoil LC 12 kW 30 mm (Most powerful in the market);
  • Opticoil LC: Liquid Cooled for more power and increase Work Roll temperature;
  • ROI in just a few months.

The Optimal Approach!

Zone-controlled lubricant sprays and Comaintel’s induction Opticoils (Induction Heating on full roll width) correct even complex shape variations, by both heating and cooling the work roll to directly attack loose and tight regions of the profile.

Comaintel’s Induction System suggested for Edge Heating :

Comaintel’s Induction System suggested for Preheating or Full width Heating :


Steel Rolling Profiling Control

Case Studies