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
  • B22D11/10—Supplying or treating molten metal
  • B22D11/11—Treating the molten metal
  • B22D11/114—Treating the molten metal by using agitating or vibrating means
  • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields

Definitions

• the invention relates to a process for the continuous casting of steel, in particular slabs, the liquid core being stirred in the region of the mold by the action of electromagnetic forces.
• the strand is stirred as usual during these events, the strand is locally "stirred", i.e. it is stirred too long on the same section of the strand.
• an etching or a sulfur impression of a strand cross section shows a very sharp transition between the outer zone, which at the time of stirring, has already solidified and the inner globulitic zone. This sharp transition is visually visible on the rolled product, therefore undesirable and deteriorates the quality. Difficulties may also arise in the case of pouring because the intended solidification of the metal located in the area of the bathroom mirror is disturbed, because the thin shell formed at the end of the strand melts as a result of the flow of hot steel brought in by the strong stirring movement. This increases the risk of breakthrough when the strand is subsequently pulled off.
• This object is achieved in that the electromagnetic forces are changed after the size of the pull-out counter-speed.
• An advantageous solution for changing the electromagnetic forces causing the bath movement is brought about by controlling the stirrer output.
• Another solution could e.g. exist by changing the stirrer distance from the strand.
• the stirrer output can be changed by changing the current and / or the voltage in the stirrer.
• a particularly simple regulation within the scope of the invention can consist in that the stirrer is switched off when the speed falls below a preselected pull-out speed, for example 80%. If the above limit of the pull-out speed is subsequently exceeded, the stirrer is switched on again. This so-called one-point control requires little equipment. If steel of different composition is poured from a number of pans in a sequential casting, separating plates are usually placed in the mold between the steel of the different batches in order to avoid a long transition piece. This requires a reduction in the pull-out speed. In this case, too, the stirrer output is changed accordingly, so that there is no disruption to the necessary work in the area of the bathroom mirror or local over stirring.
• a preselected pull-out speed for example 80%. If the above limit of the pull-out speed is subsequently exceeded, the stirrer is switched on again. This so-called one-point control requires little equipment. If steel of different composition is poured from a number of pans in a sequential casting, separating plates are usually placed in the

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=4334697

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (3)

• 1980
  • 1980-10-30 CH CH8071/80A patent/CH650429A5/de not_active IP Right Cessation
• 1981
  • 1981-10-13 US US06/310,729 patent/US4478272A/en not_active Expired - Fee Related
  • 1981-10-23 DE DE8181108778T patent/DE3167494D1/de not_active Expired
  • 1981-10-23 EP EP81108778A patent/EP0051221B1/fr not_active Expired
  • 1981-10-27 CA CA000388850A patent/CA1237869A/fr not_active Expired
  • 1981-10-30 JP JP56173178A patent/JPS57106457A/ja active Pending

Patent Citations (5)

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