Descaling

Quality improvement and plant efficiency through effective descaling

Regarding hot rolling of steel, the quality of the rolled metal surfaces depends to a large extent on effective descaling. In order to avoid surface damage, iron oxide scale layers are therefore removed from the hot steel surface by high-pressure water spraying prior to the actual hot rolling process. The selection of the best descaling nozzles and their optimum arrangement in the process is therefore a key factor. At the same time, this enables potential energy savings to be realized, which counteract rising energy costs or result from ecological considerations.

Descaling

During descaling, the spray impact of the nozzle is of particular importance. The high impact of descaling nozzles is achieved by their specific design as flat fan nozzles with a particularly low spray depth, for which special nozzle tips are used in combination with stabilizers. Lechler descaling nozzles are well-known under the brand name SCALEMASTER® and offer the optimum conditions for high product quality, low maintenance costs and low roll wear.

Descaling

Hydro-mechanical descaling process

In hydro-mechanical descaling processes the jets are formed by special descaling nozzles which are arranged on spray headers in a so called descaling box (or mill descalers) through which the product (slab, strip, billet, bloom, beam blanket, etc.) travels. Working pressure range from 80 to 450 bar.

Because the interface bond between the scale and the steel surface can be very different a proper descaling nozzle setup is of major importance to reach best descaling results. The setup of a descaling system includes nozzle parameters and the nozzle arrangement. Both have a major influence on the descaling factors, hence the descaling performances. The impact with which the descaling water impinges on the surface is the main criteria to measure the efficiency of a descaling nozzle, this is given in N/mm2.

Lechler SCALEMASTER® Descaling Nozzles

The most exacting demands placed on the surface quality of rolled steel material combined with a further reduction in the amount of energy used can only be met by using state-of-the-art descaling nozzles.

  • MicroSCALEMASTER® with smallest dimensions for space saving mounting
  • SCALEMASTER HPS® with a remarkable increase of impact for better descaling
  • Water Stop Valve for Scalemaster nozzles to stop the water flow at low pressure

Product overview

Nozzles for descaling

Lechler SCALEMASTER® Descaling Nozzles

Lechler SCALEMASTER® descaling nozzles ensure the best surface qualities and low energy consumption.

More Technical data (pdf, 3.07 MB)

Professional reports

Descaling: Descaling system optimisation in a compact endless cast and rolling mill CEM©
Descaling: Descaling system optimisation in a compact endless cast and rolling mill CEM©Contribution paper for Rolling 2016, Graz (Austria)Jochen Munz, Jong Yeon Hwang, Sang Hyeon Lee, Young ju Ko, Jürgen FrickRead now (pdf, 631 KB)
Descaling: Energy saving and process optimization by application of the latest high efficient descaling technology
Descaling: Energy saving and process optimization by application of the latest high efficient descaling technologyContribution paper for South East Asia Iron and Steel Institute (SEAISI), Vietnam, 2016Bilal Akgül, Hubertus Wenig, Abdullah SavasciogluRead now (pdf, 1 MB)
Descaling: Descaling with high-pressure nozzles
Descaling: Descaling with high-pressure nozzlesContribution paper for the conference of the Institute for Liquid Atomization and Spray Systems (ILASS) Europe, Zurich, 2001Lothar Bendig, Miroslav Raudensky, Jaroslay HorskyRead now (pdf, 4 MB)
Descaling: Optimization of descaling nozzles in a hot strip mill
Descaling: Optimization of descaling nozzles in a hot strip millOffprint from "MPT International" Volume 23 (2000), edition 5, pages 92-96, Publisher: Verlag Stahleisen GmbH (Düsseldorf/Germany)Ernst-Ulrich Becker, Gerhard Birkemeier, Werner Büchele, Michael Degner, Lutz Devrient, Michael Nowak, Gerd ThiemannRead now (pdf, 870 KB)
Descaling: Enhanced accuracy of descaling nozzle arrangements with new complementary measurement methods
Descaling: Enhanced accuracy of descaling nozzle arrangements with new complementary measurement methodsContribution paper for European Oxide Scale Conference 2014, London (UK)Jürgen FrickRead now (pdf, 286 KB)
Descaling: Optimisation of technologies for hydro-mechanical descaling of steel
Descaling: Optimisation of technologies for hydro-mechanical descaling of steelContribution paper for SMEA Conference and Exhibition, Sheffiled Metallurgical and Engineering Association, University of Sheffield (UK)Jürgen FrickRead now (pdf, 1 MB)
Descaling: Audits of existing hydro-mechanical descaling systems in hot rolling mills as a method to enhance product quality
Descaling: Audits of existing hydro-mechanical descaling systems in hot rolling mills as a method to enhance product qualityContribution paper for The Iron & Steel Technology Conference and Exposition 2005, Charlotte N.C., USAJürgen FrickRead now (pdf, 863 KB)
Descaling: More efficient hydraulic descaling header designs
Descaling: Optimisation of nozzle arrangements on descaling headers
Descaling: Optimisation of nozzle arrangements on descaling headersContribution paper for the 4th International Conference on Hydraulic Descaling, IoM Institute of Materials, London (UK)Jürgen FrickRead now (pdf, 1 MB)
Descaling: Measurement of mathematical approximation of the impact of descaling nozzles
Descaling: Measurement of mathematical approximation of the impact of descaling nozzlesContribution paper for Hydraulic Descaling Conference, London (UK)Stefan SchürmannRead now (pdf, 9 MB)