Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/12—Accessories for subsequent treating or working cast stock in situ
  • B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/08—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling structural sections, i.e. work of special cross-section, e.g. angle steel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2201/00—Special rolling modes
  • B21B2201/14—Soft reduction

Definitions

• the invention relates to a method for producing continuous casting primary material for rolling metal profiles, in particular for rolling steel profiles.
• the invention also relates to an apparatus for performing the method.
• pre-profiles cast close to the final dimensions are used in preparation for a finish rolling with final dimensions. Their development can be traced back to carrier rolling.
• the liquid core reduction (LCR) method known in the prior art provides a mode of operation in which the strand with a liquid core is reduced to a smaller thickness from the exit thickness from the mold of the continuous casting installation — distributed over several rollers.
• the strand solidifies below the wedge-shaped first segment of the strand guide in a strand guide that is conically adjusted to the shrinkage of the strand.
• LCR offers the possibility, in particular in the case of thin slab casting plants, not only to adapt the format width in the mold, but also to adapt the format thickness during casting according to the rolling program.
• the reduction of the format thickness and the return of the strand guide to the mold exit dimension is possible at any time within a sequence.
• the desired strand thickness is set by means of rollers either via hydraulic cylinders and stops, or continuously via position-controlled hydraulic cylinders.
• both blocks and beam blanks are used as a preliminary profile in modern profile rolling mills.
• beam blanks are also used to produce U-profiles, sheet piling and special profiles.
• the unpublished patent application with the official file number 100 11 689.2 describes a process for the continuous casting of slabs and, in particular, thin slabs, in a continuous casting installation with a strand guide, comprising strand guide segments that can be adjusted a short distance below a mold, in particular with pairs of rollers, whereby to reduce segregation and Core porosity of the casting strand in the area of residual solidification is reduced in thickness by adjusting the strand guide segments.
• the process is known as soft reduction.
• a strand runs through a soft reduction section, at the start of which it has not yet solidified, but at the end of which it should be solidified, for which the casting speed is an essential operating parameter.
• the casting speed is an essential operating parameter.
• the pairs of rollers of individual segments in the soft reduction section are adjusted more closely beyond the shrinkage behavior of the strand in order to improve the internal strand quality in the area of residual solidification.
• EP 0 834 364 A1 describes a method and a device for high-speed continuous casting plants with a reduction in strand thickness during solidification, the melt preferably being poured into an oscillating mold and the strand cross-section linearly over a minimum length of the strand guide directly below the mold, the so-called casting rolls, is reduced. There is then a further strand reduction via the remaining strand guidance, the so-called "soft reduction", up to a maximum of immediately before the final solidification or bottom tip.
• This procedural measure prescribes the deformation density of the reduction in cross section so that the critical deformation of the strand shell is not exceeded, taking into account the high casting speed and steel quality.
• EP 0 177 796 B1 discloses a method for guiding and straightening a casting strand in the drawing and discharge area of a continuous sheet casting installation, wherein oppositely arranged rollers are held at a distance corresponding to the casting process by a spring force against the ferrostatic pressure of the casting strand. A cast strand area of increased strength is traced away, and when it passes between opposing rollers, the respective spring force is reduced by a small additional force.
• This proposal namely to continuously adjust the clear distance or the mouth width via hydraulic cylinders with built-in inductive displacement measurement and servo valves, requires a computational or metrological determination of the position of the sump tip.
• the object of the invention is to develop a new method and a new device of pre-profiles using blocks or beam blanks that are cast close to their final dimensions.
• a substantially more homogeneous shaping of the cast strand is to be achieved.
• the production of different pre-profiles for a profile rolling mill is also intended to significantly reduce the rolling effort for the final profiling in the finishing mill and thereby also save calibers.
• the invention provides, in a method of the type mentioned in the preamble of claim 1, that cast strands are cast in the continuous casting installation in the block profile or in another suitable casting profile (for example beam blank) and these are cast below the mold or within or below the strand guide in the area of its still liquid core using at least one pair of rollers for strand forming with profiled, preferably axially and / or radially adjustable rollers of a preforming unit to be preformed which are finished rolled in a finish rolling process to profiles with predetermined final dimensions , Furthermore, according to the invention, a simple and maintenance-friendly strand guide is created for a large number of different strand cross sections.
• an extruded profile with a liquid core i.e.
• a large number of different and also asymmetrical continuous casting profiles are produced as preliminary profiles.
• an asymmetrical shaping of the strand shell advantageously leads to a substantially more homogeneous shaping since the liquid core does not experience any compressive or tensile stresses.
• Another advantage of the invention results from the higher number of different pre-profiles for a profile rolling mill, because this reduces the rolling effort. adorned and additionally saved caliber.
• asymmetrical pre-profiles When using asymmetrical pre-profiles, a more homogeneous forming is possible during rolling, so that the caliber and valve stress are significantly reduced and the service life is increased.
• the strand is formed in stages with at least one pair of rollers.
• the forming can also be done using other adjustment means, e.g. adjustable profiled runners, which run along a predetermined path at the casting speed, lift off and return to the starting position at a higher speed.
• the method according to the invention provides that a pre-profile is shaped in the preform unit in such a way that its cross-sectional shape and mass distribution are similar to the finished profile.
• a further embodiment of the method according to the invention provides that the profiling of the rollers is designed such that their employment results in as many pre-profile dimensions as possible.
• the method according to the invention provides that the casting of a cast strand into the preliminary profile is carried out with one or more pairs of rollers, the number of which depends on the profile cross section which can be specified in each case.
• a device for producing continuous casting material for the rolling of metal profiles, in particular for the rolling of steel profiles, comprising a continuous casting system with a block or other suitable casting profile mold provides that below the mold or within or below the strand guide in the A preforming unit with at least one pair of rollers with profiled, preferably axially and / or radially adjustable rollers is arranged in the area of a still liquid core of a casting strand emerging from the mold in such a way that the rollers close the block or the casting profile as it passes through the preforming unit Form pre-profiles.
• Figure 1 in cross-section cast continuous profiles with a liquid core when reducing to profiles close to final dimensions
• FIG. 2 shows the forming of a cast strand according to the invention with several pairs of rollers
• FIG. 3 shows a number of different pre-profiles which can be produced from a cast strand of a block or beam blank mold according to the invention
• FIG. 4 shows a device for producing continuous casting pre-profiles in accordance with the invention
• Figure 5 shows the principle of pre-profiling in a forming step.
• Figure 1, namely Figure 1 a to 1c shows work steps in the casting reduction of cast continuous casting profiles 4a, 4b, 4c to profiles close to the final dimensions between profile rollers 2a, 3a; 2b, 3b and 2c, 3c.
• FIG. 2 shows the principle of pre-profiling a casting strand, for example from a block mold, as it passes through the pairs of rollers 2b / 3b, 2a / 3a.
• the rollers 2, 3 are profiled and press the strand shell against the ferrostatic internal pressure of the liquid core to a profile, similar to the profile cross section 4.1 in Fig. 3. Because the strand shell is still easily deformable compared to the liquid core, the process is not so much about a rolling process, but more about a spinning process. The number of required pairs of roles depends on the respective profile cross-section. The decrease in each pair of rolls must not be so great that the strand shell is damaged.
• Fig. 2 the principle of pre-profiling between two pairs of rollers is shown purely by way of example.
• the slightly smaller diameter roller pair 2b, 3b presses a flat concave groove 4, while the trailing roller pair 2a, 3a with a slightly larger diameter of its profiling 9 further reforms the concave shape according to the format 4.1 or 4.2 in FIG. 3.
• a zone of pure strand guidance can follow after the forming area.
• the pre-profiling of cast blocks or beam blanks with a still liquid core takes place in smaller steps, so that one can speak of a liquid core shaping during the pre-forming.
• Figure 3 shows different continuous casting pre-profiles that can be produced by a liquid core shaping process. For example:
• Beam blank formats with a large web thickness and a small incision depth for rolling double T profiles (cf. format 4.1).
• - Beam blank formats with different flange heights and widths, e.g. for rail rolling (see Format 4.2)
• - Beam blank formats with locally increased web thickness e.g. for rolling groove profiles (see Format 4.3)
• Beam blank formats with one-sided flange reduction enable, for example, U-profile rolling (see Format 4.4),
• Blocks with a trapezoidal cross-section are suitable, for example, for rail rolling (see format 4.5 / 4.6 and 4.7),
• Blocks with a slightly U-shaped cross-section are suitable, for example, for sheet piling (see Format 4.8),
• Sheet pile rolling suitable see Format 4.9
• - round profile e.g. for bar and wire rolling (see format 4.10)
• FIG. 4 shows a device for producing continuous casting starting material according to the method of operation referred to as liquid core shaping (LCS), comprising a continuous casting installation with a block or beam blank mold 5.
• LCD liquid core shaping
• a preforming unit 7 with profiled, axially and / or radially adjustable rollers 3 is arranged below the mold 5 or below a strand guide segment 6 'in the region of a still liquid core of the casting strand 1 emerging from the mold 5.
• the rollers 3 form the beam blank 1 as they pass through the preforming unit 7 into preforms 4 (cf. FIG. 3).
• a self-supporting extrusion profile should be achieved that does not require any additional extrusion support.
• a further extruded guide segment 6 ' is arranged after the preforming unit 7 and now has guide rollers with corresponding profiles, such as the initial profiling rollers 3 of the unit 7.
• the strand guide segment 6 is smooth, non-profiled rollers 2.
• 5 shows the principle of pre-profiling the cast strand 1 in a forming step by means of the rollers 2a, 3a.
• Lateral guide rollers 8a, 8b give the flange of the preliminary profile lateral support.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Rolling (AREA)
• Continuous Casting (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7682188

Family Applications (1)

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Family Cites Families (5)

• 2001
  • 2001-04-21 DE DE10119550A patent/DE10119550A1/de not_active Withdrawn
• 2002
  • 2002-03-15 TW TW091104963A patent/TW520308B/zh not_active IP Right Cessation
  • 2002-03-21 EP EP02706775A patent/EP1381482B1/fr not_active Expired - Lifetime
  • 2002-03-21 WO PCT/EP2002/003147 patent/WO2002085559A1/fr not_active Application Discontinuation
  • 2002-03-21 DE DE50200636T patent/DE50200636D1/de not_active Expired - Lifetime
  • 2002-03-21 AT AT02706775T patent/ATE270934T1/de active

Non-Patent Citations (1)

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