In a hot strip mill, the coilbox is arranged between the roughing stand and the finishing mill. Basically it forms transfer bars into coils. In doing so, material and heat are accumulated, providing several positive effects on the material to be rolled and the production process. The patented mandrel-less transfer of the coil from the coiling to the uncoiling station prevents the inner windings from cooling down. By this, temperature losses of the transfer bar are minimized. Applied in combination with the HIBOX® insulation hoods - also from SMS group - the transfer bar temperature is even more homogeneous.

But also considered individually, the mandrel-less coilbox equalizes the temperature over the transfer bar length resulting in lower required rolling energy and consequently in a reduction of the carbon footprint. At the same time the better transfer bar temperature allows an expansion of the product range to thinner gauges, improve the hot strip quality and lead to a higher rolling stability - without thermal energy input from outside. SMS group holds the thin gauge record in conventional hot strip mills thanks to the mandrel-less coilbox! Another important effect of using a coilbox: It allows a more compact hot strip mill layout.

The mandrel-less coilbox can be easily retrofitted in existing plants. Existing coilboxes with transfer mandrel can be revamped to incorporate all the benefits of a mandrel-less coilbox.

Some numbers underline the benefits of mandrel-less coilbox:

  • Compensation of temperature drop head to tail: up to 100°C
  • Energy savings: up to 10,000,000 kWh/year
  • OPEX savings: up to 1,000,000 EUR/year
  • Proven share of thin gauge (<2.0 mm) with coilbox in SMS group conventional HSM: up to 40%
  • Number of coilboxes supplied by SMS group: 33