Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B28/00—Maintaining rolls or rolling equipment in effective condition
  • B21B28/02—Maintaining rolls in effective condition, e.g. reconditioning
  • B21B28/04—Maintaining rolls in effective condition, e.g. reconditioning while in use, e.g. polishing or grinding while the rolls are in their stands
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B28/00—Maintaining rolls or rolling equipment in effective condition
  • B21B28/02—Maintaining rolls in effective condition, e.g. reconditioning

Definitions

• the invention relates to a method for working up rolls of a hot rolling stand for aluminum materials for the production of rolling mill products, in which the roll is worked up after or during use by machining the roll surface.
• rolls for the production of rolling mill products have a roll surface which is adapted to the respective intended use.
• work rolls for hot or cold rolling of metal strips have a roll surface with a defined roughness in order to ensure that the rolling stock is gripped securely by the rolls and that a defined surface of the rolling stock is produced.
• Other types of rolls such as back-up rolls, strip drawing rolls or the like, also have a defined roll surface, which ensures that these rolls function properly.
• the work rolls used in the hot rolling of aluminum strips have a polished structure on their surface, which on the one hand ensures the production of the desired surface properties of the rolling stock and on the other hand contributes to the safe gripping of the rolling stock by the rolls, which prevents slipping in the roll gap.
• aluminum oxide or aluminum particles or - depending on the rolled alloy - magnesium oxide or magnesium particles settle in the recesses of this ground structure. These particles are compressed in the recesses by the high rolling pressure force in such a way that they fill the recesses of the ground structure in a compact and very resistant manner. This in turn means that the grinding structure on the roll surface is no longer effective after a certain period of use of the roll during rolling.
• the deposits formed on the roller surface are also referred to as rolled shirts.
• rolls are cost-intensive products to be manufactured, they are, as is known from the prior art, not completely replaced after the formation of a rolled shirt or the like, but removed and worked up by machining the roll surface. After working up, the rolls have the desired properties on their roll surface and can be used again. It is known from the prior art to refurbish the rolls by machining the roll surface using mechanically abrasive methods, such as grinding. In this process, the deposited impurities and the material of the roller itself are removed from the roller surface in a defined manner in order to produce an unused roller surface. In some cases, the roller surfaces are also subjected to a new coating or hardening after the mechanical abrasive treatment.
• the rolls are finally used up after a certain number of work-ups, ie also after Refurbishment not reusable. On the one hand, this is due to the change in the geometric properties, on the other hand, it is also due to the reaching of material layers of the roller material, which are no longer suitable for further processing due to a lack of strength or the like.
• the present invention is based on the object of specifying a method for reconditioning rollers for the production of rolled products, which ensures simple, fast and inexpensive reprocessing of the rollers.
• the previously derived and shown object is achieved in that the roller surface is processed with the aid of a liquid jet and the liquid pressure is set to approximately 50 to 250 MPa, preferably 70 to 150 MPa, when the liquid jet is generated.
• Liquid jet can be removed almost without residue.
• the processing of the roll surface with the aid of a liquid jet is particularly advantageous in that the original roll surface is hardly changed thereby, so that, for example, there is no decrease in the roll diameter during processing.
• the fact that the actual roll surface is almost unchanged during processing with the aid of a liquid jet means that the roll remains true to size even after the processing.
• the requirements for processing with the aid of a liquid jet are therefore compared to mechanical abrasive processes, in which dimensional accuracy must be guaranteed, are much lower.
• the processing of the roll surface with the help of a liquid jet can be done significantly faster than the processing of the roll surface with mechanically abrasive processes such as grinding.
• the method according to the invention can also be combined with the mechanically abrasive methods known from the prior art.
• liquid pressure when generating the liquid jet according to the invention is set to about 50 to 250 MPa (10 6 Pa), preferably 70 to 150 MPa, ensures that the residues and contaminants on the rollers are reliably detached.
• mechanically driven piston pumps plurize such pressures, in some cases with the additional use of hydraulic pressure intensifiers.
• the method according to the invention experiences a first advantageous embodiment in that the roller surface is processed for processing exclusively with the aid of a liquid jet. It has been found that the processing of the roller surface with the aid of a liquid jet for processing rollers is so thorough that further processing of the roller surface, in particular by brushing, is unnecessary. In particular, coatings of the roller surface, which have been applied, for example, to increase the strength of the roller surface, generally also remain obtained during processing with the help of a liquid jet.
• the teaching according to the invention is advantageously further developed in that the machining is carried out within rolling breaks.
• the rolling process there are regular breaks in the rolling, which result from the system, for example, from the transport of a new ingot to the rolling stand or the like. These roll breaks can easily be used to process the rolls according to the invention.
• water is used as the liquid further optimizes the method according to the invention with regard to environmental compatibility, occupational safety and the costs associated with the method. With the use of water, trouble-free compliance with explosion safety is guaranteed.
• the water obtained during the processing can be easily treated within the framework of customary disposal measures or can remain in a water cycle, for example the emulsion water cycle of a hot roller.
• the use of alternative liquids is possible to produce the liquid jet used for processing.
• the quality of the water used must be adapted to the respective application.
• the addition of particles in an appropriate dosage is also conceivable in order to increase the cleaning power or to process the roll surface in a shape-changing manner.
• Fig. 1 shows schematically a greatly enlarged section through the roll surface of a work roll
• Fig. 2 is a perspective view of a roller during processing using the method according to the invention.
• Fig. 1 shows the profile of a work roll of a hot rolling stand for aluminum alloys.
• the actual roller material 1 is shown hatched. In the present case, it is a steel roller. For other applications e.g. cast iron rollers are also used. It can be clearly seen that the roller surface is contoured on the scale shown and has a plurality of elevations 2 and depressions 3. These elevations 2 and depressions 3 provided in the roll material 1, generally referred to as roughness, ensure, when using the work roll shown, as already mentioned, among other things, a reliable gripping of the rolling stock by the rolls and a desired one
• the roller surface shown in FIG. 1 belongs to a roller that has already been used to a considerable extent.
• 3 aluminum oxide and aluminum particles have accumulated in the depressions during the hot rolling of aluminum strips, which particles have been compressed to form deposits 5 by the high rolling pressure.
• the deposits 5 shown in FIG. 1 already cover part of the elevations 2, as a result of which the grip between the roll surface and the rolling stock is reduced. This increasingly leads to effects such as the slipping of the rollers, the detachment of deposits 5 that remain on the surface of the rolling stock, and to the pointally greater accumulations of deposits 5 that leave impressions on the surface of the rolling stock.
• the roll surface shown in Fig. 1 must be worked up to continue to produce perfect rolling stock.
• the work-up takes place in that the roll surface is processed with the aid of a liquid jet, as shown in FIG. 2.
• a liquid jet as shown in FIG. 2.
• water is preferably used as the liquid, since a hot / oil emulsion is used for hot rolling itself, so the water is not a foreign substance in the process.
• a roller 6 shown in FIG. 2 has a roll shirt 7 consisting of the deposits 5 shown in FIG. 1, which has to be removed during processing.
• the work-up takes place in that the roller surface 8 is processed with the aid of a liquid jet 9 which emerges from a jet lance 10.
• the rolled shirt has been removed.
• the refurbishment according to the invention shown in FIG. 2 can take place both in the installed and in the removed state of the roller 6.
• the jet lance 10 can be guided manually or automatically. It is advisable to arrange a device within the roll stand which automatically guides the jet lance 10 over the roll surface 8 when the roll 6 is being worked up, in order to remove the roll shirt as soon as this is necessary. This is also possible during the rolling process.
• a water jet with a pressure of approximately 200 MPa without the addition of particles was used for the processing in the described processing.

Landscapes

• Mechanical Engineering (AREA)
• Engineering & Computer Science (AREA)
• Metal Rolling (AREA)
• Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
• Grinding Of Cylindrical And Plane Surfaces (AREA)
• Bakery Products And Manufacturing Methods Therefor (AREA)
• Seasonings (AREA)
• Detergent Compositions (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)
• Printing Plates And Materials Therefor (AREA)
• Treatment Of Fiber Materials (AREA)
• Paper (AREA)
• Rolls And Other Rotary Bodies (AREA)
• Machines For Manufacturing Corrugated Board In Mechanical Paper-Making Processes (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)

Priority Applications (9)

Applications Claiming Priority (4)

Publications (1)

Family

ID=7703705

Family Applications (1)

Country Status (14)

Families Citing this family (6)

Citations (3)

Family Cites Families (4)

• 2001
  • 2001-10-23 EP EP01125177A patent/EP1304174A1/de not_active Withdrawn
• 2002
  • 2002-06-29 AU AU2002325855A patent/AU2002325855B9/en not_active Ceased
  • 2002-06-29 CA CA002457168A patent/CA2457168A1/en not_active Abandoned
  • 2002-06-29 AT AT02760208T patent/ATE289532T1/de not_active IP Right Cessation
  • 2002-06-29 BR BR0211724-0A patent/BR0211724A/pt not_active Application Discontinuation
  • 2002-06-29 CN CNB028177967A patent/CN1282507C/zh not_active Expired - Fee Related
  • 2002-06-29 WO PCT/EP2002/007214 patent/WO2003035292A1/de active IP Right Grant
  • 2002-06-29 EP EP02760208A patent/EP1436103B1/de not_active Revoked
  • 2002-06-29 US US10/485,197 patent/US20040244455A1/en not_active Abandoned
  • 2002-06-29 RU RU2004102899/02A patent/RU2280520C2/ru not_active IP Right Cessation
  • 2002-06-29 PL PL02367793A patent/PL367793A1/xx unknown
  • 2002-06-29 DE DE50202340T patent/DE50202340D1/de not_active Revoked
  • 2002-06-29 JP JP2003537844A patent/JP3854274B2/ja not_active Expired - Fee Related
  • 2002-06-29 ES ES02760208T patent/ES2238061T3/es not_active Expired - Lifetime
  • 2002-06-29 KR KR1020047002357A patent/KR100594644B1/ko not_active IP Right Cessation

Patent Citations (3)

Non-Patent Citations (1)

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