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Grades hot rolling mills

In its program, Production and Engineering Company ENCE GmbH highlights the most significant metallurgical equipment; this equipment complies with the highest international quality standards and may be offered to customers at competitive prices.

Description

Hot rolling sheet mills:

  • Broad-strip mills
  • Plate mills

Hot rolling section mills:

  • Structural and beam-rolling mills
  • Heavy-, medium-, and small-section mills
  • Wire mills
  • Combination small-section wire mills

Hot Rolling Mills

In modern steelmaking industry, about half of all products are hot-rolled, therefore, the process and equipment are subject to the highest requirements for dimensional accuracy and final metal properties.

A hot rolling mill is a unit that includes various mechanisms: preparing ones, those that dress at high temperatures and those for metal final processing. The key mechanism in a rolling mill is a system of rolls, which is in direct contact with the metal, giving it the necessary geometric dimensions, shape, quality and surface properties.

As a rule, two work rolls are in a direct contact with the material.  

The most common are two, three and four-roll mills:

  • Two-roll mills are used for large profiles and thick sheets;
  • Three-roll mills are used for high-quality profile and medium-grade sheets. In three-roll mills, the reverse movement of the sheet is achieved without changing the direction of the drive rotation;
  • Four-roll mills are widely used in the rolling of various types and ranges of rolled products.

Universal stands, in addition to horizontal, have vertical rolls that compress metal on the right and left. They are used for rails and broadband I-beams rolling.

Recently, all stages of the long products production, from the casting and finishing to the final processing of products, are tried to be combined into one production line. This allows to eliminate some labor-intensive operations (ingot processing, heating, transportation, etc.) and reduces metal consumption and the installation area, and simplifies automation. The improved efficiency is achieved due to lower energy costs (unnecessary operations), eliminating the cost of equipment and labor needed for the transportation of products.

The main disadvantage of this method is the limitation of the entire system capacity by the speed of the slowest operation, which is blanks casting. To solve this, either several molds are used in continuous billet casting machines (CCM), or the ingots are fed to the rolling mill without separation, i.e. continuously.

Hot rolling mills can make products with different profiles for different needs and applications. Profiles depend on the shape and size of the rolls.

  • steel framework

It is mainly used as a reinforcing layer in building construction when reinforced concrete structures are manufactured. Such steel framework has a diameter of 8 mm, is made of carbon steel and delivered in measured pieces of 6 or 12 m. Steel framework of smaller diameters (6-9 mm) can be supplied in coils and modified directly at site (unwinding, cutting). Steel framework for reinforced concrete, as a rule, has ribs (corrugation) for better adhesion to concrete, however, there is also a smooth steel framework that is not used in construction.

  • rolled wire

As a rule, it is a thick wire with a diameter of 5 to 10 mm wound into coils (from 1 mm for the production of electrical cables). It is made by a stepwise reduction from all sides on the mills. The wire is then made into electric cables, rod, nails and much more.

  • T-bar, I-beam, channel bar

Hot-rolled beams are made on mills using stands and rolls of a special shape. Beams are widely used in construction as load-bearing structures of floors, bridges and rack structures, structures of various protrusions (balconies, canopies), to make window and doorways. In addition, beams are widely used for the construction of integral frames of metal structures as both horizontal and vertical elements. The dimensions of the beams are standardized - the height of the profile is from 50 to 600 mm, the length is a multiple of 4 to 12 meters or unmeasured. As materials, carbon or low alloy steel are usually used.

  • angle bar

The production and use of a steel angle bar is generally similar to those of T-beams and channel bars, however, the angle bar is of less weight, smaller and able to withstand lower loads. It is difficult to think of metal structures that do not have a steel angle bar as a main or as an additional element. In combination with channel bars and T-bars, angle bars are used for interfloor overlapping, window and doorways and various metal structures. As a cheaper profile, the angle bar has proven itself in farm household for creating new metal structures or repairing and strengthening the existing ones. Simple or low-loaded metal structures can consist only of angle bars.

Sizes of angle bar legs are from 20 to 250 mm, the length is a multiple of 4 to 12 meters. Material is structural or low alloy steel.

  • strip

Strip rolling has the most universal and used application among other profiles. In addition to the use of a steel strip itself for decorating building facades, when creating gratings, fences, it is used as a blank for creating cutting tools, washers, nuts, large springs and many other elements. In addition welded channel bars and T-bars are made of steel strip, which have some advantages in comparison with hot-rolled ones and they are widely used.

The strips range from 20 to 200 mm, the thickness is from 4 to 18 mm. The length of strip made of low alloy or carbon steel is from 3 to 12 meters, and the length of that made of alloy steel is up to 6 meters. The strip can be also delivered as rolled.

  • round bar, square bar, hexagon bar

Rolling of such sections is made by compressing from all sides. The products are widely used in construction, mechanical engineering and also as blanks for hardware production (bolts, screws) and various parts and tools. They can be of ordinary or high precision made of carbon or alloy steel. The diameter of the round bar is from 5 to 250 mm, the diameter of the hexagon inscribed circle is from 4 to 100 mm, the square bar side is from 4 to 200 mm. The length is a multiple of 2 to 12 m or ‘endless’ when rolled and having small diameter/side size. A steel square can be rolled up but not more than by 24 degrees.