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

Definitions

• the invention relates to a process for the production of cast strands in billet or block format, the strands being guided between pairs of rollers.
• the strand is deliberately reduced in thickness in the area of residual solidification with one or preferably several pairs of rollers.
• the thickness reduction in the area of the soft reduction can take place uniformly or unevenly.
• strand cross-sections are designed for soft reduction with one-sided or multi-sided profile elevations or profile depressions in order to achieve a significant improvement in the inner strand quality with a comparatively low power requirement.
• the soft reduction begins in the straightening area of the cast strand by turning on the straightening rollers. To do this, the speed and strand cooling must be set so that the residual solidification takes place in the straightening area. At high casting speeds and / or large casting cross sections, the casting radius must be increased considerably. This leads to considerable additional costs for the corresponding system. Furthermore, an adjustment of the rollers against spacers or the use of preferably position-controlled hydraulic cylinders is required in order to avoid strand reduction in the wrong place with smooth rollers.
• Document US 3,628,594 describes a device for reducing the cross section of a cast strand, comprising a pair of drivable rollers in a horizontal plane and pairs of drivable rollers arranged in vertical planes on opposite sides of the strand.
• the pairs of rollers through which the strand passes are against each other by means of piston / cylinder units which can be adjusted by hydraulic medium and which serve to reduce the vertical and horizontal cross-sectional dimensions of the cast strand.
• the unpublished German patent application with the file number 101 44 234.3 describes a method and a device for optimizing the quality of cast strands with round or approximately round cross sections in the area of soft reduction.
• the casting strands below the mold in the area of residual solidification are deformed in at least one reduction level by adjustable rollers to improve the internal quality.
• the round or approximately round casting cross-section can be deformed by rollers that can be adjusted on both sides and are offset by 90 ° to the reduction level by an amount between 5% and 60% of the main reduction in the area of residual solidification in order to increase the internal quality by further core compaction increase.
• the document JP 12 37 062 provides that internal cracks in a cast strand during straight bending, even at higher casting speeds, are avoided by the strand having a declining trapezoidal format.
• the strand is formed in a mold with a trapezoidal casting format of the inner wall surfaces, the width of which is greater on the inside of the arch than the width of the form on the outside of the arch, in order to form the retrograde trapezoidal format. This process reduces the tensile stress in the first area of the upper format side of the cast strand and the casting speed can be increased.
• the document JP 63 21 5353 shows a method for easier processing of a cast strand by executing the casting process using a water-cooled mold with a round or polygonal format.
• the continuous casting machine is followed by roll groups for step-by-step roll reduction, which carry out the intended reduction alternately vertically and horizontally.
• step-by-step roll reduction which carry out the intended reduction alternately vertically and horizontally.
• Document JP 12 02 342 suggests, for reducing the tensile stress in the solidified area of a cast strand and for improving its production from molten steel, the formation of notches in part of the upper format side of the cast strand, and a shaping of the notched area during the continuous casting process - ses. After the cast strand is pulled vertically out of the mold, it is first bent in a circular shape and then led to a horizontal stretching area.
• the strand is guided into the horizontal stretching area with upper and lower pinch rollers in order to stretch it into the horizontal format.
• the strand is cut using a cutting torch on the outer side of the horizontal stretching area. This process reduces the tensile stress on the strand in the solidified area of the boundary layer at the top, and a continuous casting process is made possible even at increased casting speeds. In addition, structure cracks are avoided and productivity is significantly improved.
• the document JP 21 42 654 enables the production of a round cast strand without internal crack formation by stretching the cast strand by means of stretching rollers and pulling by means of rotating pinch rollers after solidification. With this method, bending stress is only effective in the non-solidified area of the strand, which reduces the formation of internal cracks.
• the invention has for its object to provide a method and a casting machine for billet and / or block formats, in which the casting radius is not determined by the soft reduction, but is chosen inexpensively, in particular for reasons of casting technology and quality can.
• the invention proposes that the strands in their straightening area be used with profiled rollers with profile increases on one or more sides or profile recesses are formed, and that they are subjected to a soft reduction in the casting direction behind the straightening area by means of at least one pair of rollers with smooth rollers.
• pairs of rollers in the area of the soft reduction section are opened or closed in accordance with the position of the swamp tip.
• the soft reduction can preferably be carried out with a pair of rollers.
• the position of the sump tip is calculated using computer models and / or measurement technology, e.g. B. is determined by displacement or force measurement, after which the pairs of rollers are employed accordingly.
• This measure is particularly expedient in the case of steel grades with strong tendencies towards segregation and / or core porosities, with profile elevations or profile depressions of the strand cross section being provided on all four sides.
• a casting machine for the production of cast strands with billet or block format with formation of one- or multi-sided profile elevation is characterized in that profiled roller pairs are assigned to the straightening region of the strands, and that at least one roller pair with smooth rollers is arranged downstream for the area of soft reduction ,
• Figure 1 A casting machine with mold and subsequent
• Figures 2a, 2b, 2c strand cross sections C, D, E with one or more sides
• FIGS. 3a, 3b, 3c strand cross sections F, G, H with single- or multi-sided profile depressions according to the invention
• FIG. 4a shows a profiled roller for producing profile elevations
• Figure 4b shows a profile roll for forming profile recesses.
• FIG. 1 shows a casting machine with the mold 1 when steel melt 10 is given in and a cast strand 2 is formed below the mold.
• the strand 2 with the casting radius R passes through a deflection, from the vertical casting direction in the horizontal direction 13 with the tangent point 3.
• This tangent point 3 is located approximately in the middle of the straightening area A, with the straightening rollers 4, 5, 6 , which is followed by the soft reduction area B.
• the soft reduction takes place in the soft reduction area B with the roller pairs 7, 8, 9 using smooth rollers.
• the position of the bottom of the swamp in the soft reduction area B is determined with the aid of computer models or by measurement, e.g. B. determined by distance or force measurement, after which the pairs of rollers 7 - 9 are employed accordingly.
• FIGS. 2a to 2c show the formation of strand cross sections according to the invention with one or more sided profile elevations (h, b) with the resulting cross-sectional shapes C, D, E.
• FIGS. 3 a to 3 c show strand cross sections according to the invention, which are formed with profile recesses (-h, b) and have the cross-sectional shapes F, G, H.
• the respective profile recesses are marked with -h (or -h ') on the opposite side.
• profiled rollers 4 to 6 used to produce the profile shapes correspond to the training according to Fig. 4a with the format 11, while profile rollers 12 are formed for the production of profile recesses.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)
• Metal Rolling (AREA)
• Multi-Process Working Machines And Systems (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7704458

Family Applications (1)

Country Status (6)

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Family Cites Families (7)

• 2001
  • 2001-11-06 DE DE10153960A patent/DE10153960A1/de not_active Withdrawn
• 2002
  • 2002-11-04 EP EP02785358A patent/EP1441871B1/fr not_active Expired - Lifetime
  • 2002-11-04 WO PCT/EP2002/012263 patent/WO2003039789A2/fr active IP Right Grant
  • 2002-11-04 US US10/494,590 patent/US20050067135A1/en not_active Abandoned
  • 2002-11-04 AT AT02785358T patent/ATE359887T1/de not_active IP Right Cessation
  • 2002-11-04 AU AU2002350668A patent/AU2002350668A1/en not_active Abandoned
  • 2002-11-04 DE DE50209992T patent/DE50209992D1/de not_active Expired - Lifetime
• 2007
  • 2007-05-24 US US11/807,141 patent/US20080041554A1/en not_active Abandoned
• 2009
  • 2009-03-19 US US12/383,234 patent/US20090178777A1/en not_active Abandoned

Non-Patent Citations (1)

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