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
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
• • 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
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0637—Accessories therefor
  • B22D11/0648—Casting surfaces
  • B22D11/0651—Casting wheels
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/06—Alloys based on copper with nickel or cobalt as the next major constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon

Definitions

• the invention relates to a casting roll for a two-roll caster.
• the temperature gradient between the surface and the back in combination with the cyclic change in the surface temperature of the casting rolls causes thermal stresses in the surface area of the shell material.
• Another disadvantage of the proven mold material CuCrZr is the relatively low hardness of about 110 HBW to 130 HBW for this application.
• the solidified steel particles are then forced into the relatively soft surfaces of the casting rolls, thereby significantly affecting the surface quality of the cast strips of about 1.5 mm to 4 mm thickness.
• the lower electrical conductivity of a known CuNiBe alloy with an addition of up to 1% niobium leads to a higher surface temperature compared to a CuCrZr alloy. Since the electrical conductivity is approximately proportional to the thermal conductivity, the surface temperature of a shell of a casting roll of the CuNiBe alloy is compared to a casting roll with a jacket of CuCrZr with a maximum temperature of 400 ° C at the surface and 30 ° C. increase the back to about 540 ° C.
• ternary CuNiBe- or CuCoBe alloys generally have a Brinell hardness of over 200 HBW, but reaches the electrical conductivity of the standard semi-finished products produced from these materials, such as rods for the production of resistance welding electrodes or sheets and strips for the production of springs or Leadframes, possibly in the range of 26 Sm / mm 2 to about 32 Sm / mm 2 values. Under optimum conditions, only a surface temperature on the shell of a casting roll of about 585 ° C would be achieved with these standard materials.
• a curable copper alloy as a material for the production of continuous casting molds is both from the U.S. Patent 4,377,424 as well as from the DE 100 18 504 A1 known. Curable copper alloys can also be used as a material for the production of foundry molds ( US 4,599,120 A ). In principle, the requirements placed on the materials of continuous casting molds and foundry molds are different from those for casting rolls.
• Alloys with these compositions have disadvantages in the hot workability due to the relatively high alloy element content.
• high degrees of hot working are required to, starting from the coarse-grained cast structure with several millimeters grain size, a finer-grained product with a grain size ⁇ 1.5 mm (according to ASTM E 112) to achieve.
• for large casting rolls are so far only with great effort enough large ingots produced with sufficient quality;
• technical forming facilities are hardly available in order to realize a sufficiently high amount of hot kneading for recrystallization of the cast structure into a fine grain structure with reasonable outlay.
• the invention is - based on the prior art - the object of the invention to provide a casting roll as part of a Zweiwalzeng screenstrom which can be exposed to near net near final casting of strips of non-ferrous metals readily changing temperature stresses and high rolling pressures with a long service life.
• the mantle is made by the casting, hot working, solution annealing at 850 ° C to 980 ° C, cold working up to 30% and curing at 400 ° C to 550 ° C over a period of 4-32 hours, with the sheath giving a maximum of has a mean grain size of 1.5 mm according to ASTM E 112, a hardness of at least 170 HBW and an electrical conductivity of at least 26 Sm / mm 2 .
• a casting roll formed in this way as part of a two-roll casting installation it is possible to increase the speed during casting of a non-ferrous metal strip, in particular of aluminum or an aluminum alloy, by more than twice compared with a roll arrangement equipped with pure steel jackets.
• a significantly improved surface quality of the cast strip is achieved.
• a significantly longer life of the shell is guaranteed.
• the casting roll can be designed as a hollow cylinder, that is to say inherently rigid without a core.
• the surface which comes into contact with the strips to be cast can also be part of a jacket with a core, in particular a steel core.
• the jacket can then be shrunk, flipped or pulled onto such a core as a carrier and then mechanically clamped.
• the envelope surface of the surface of the casting roll may be cylindrical or cambered to compensate for roll deflection, if desired.
• a further improvement of the mechanical properties of the shell, in particular an increase in the tensile strength can be advantageously achieved according to claim 2, that the copper alloy 0.03% to 0.35% zirconium and 0.005% to 0.05% magnesium.
• the copper alloy for the cladding contains ⁇ 1.0% cobalt, 0.15% to 0.3% beryllium and 0.15% to 0.3% zirconium.
• the ratio of cobalt to beryllium is between 2 and 15.
• this ratio of cobalt to beryllium from 2.2 to 5.
• the copper alloy in addition to cobalt contains up to 0.6% nickel.
• the copper alloy of the shell contains up to a maximum of 0.15% of at least one element of the group comprising niobium, manganese, tantalum, vanadium, titanium, chromium, cerium and hafnium.
• the shell according to claim 8 in the cured state has a mean particle size of 30 microns to 500 microns according to ASTM E 112, a hardness of at least 185 HBW, a conductivity between 30 and 36 Sm / mm 2 , a 0, 2% proof stress of at least 450 MPa and an elongation at break of at least 12%.
• the jacket is provided with a coating which reduces the heat permeability or evenens out the heat flow
• the product quality of the cast-off tape can be further increased from a non-ferrous metal, but in particular aluminum or an aluminum alloy.
• This coating is effected specifically due to the performance of the jacket of a copper alloy in particular an aluminum strip characterized in that at the beginning of a Abg discern- and rolling process from the interaction of copper with aluminum on the surface of the shell forms an adhesion layer from which then in the course of the casting process aluminum penetrate into the copper surface and there form a stable resistant diffusion layer whose thickness and property are substantially determined by casting speed and cooling conditions. This improves the surface quality of the aluminum strip and consequently significantly increases product quality.
• the surface of the casting roll may be formed smooth according to claim 11. This design can be achieved in particular by rolling. In this way, compressive stresses are induced in the edge zone which allow additional resistance to cracking and crack propagation in order to increase the life of the casting roll.
• the surface of the casting roll is textured. Texturing can be done, for example, by cutting, rolling, eroding or blasting. By such measures, the heat transfer coefficient can be influenced in a targeted manner.
• Such a substance may be a ceramic material in addition to a metallic material, such as in particular nickel or a nickel alloy.
• a metallic material such as in particular nickel or a nickel alloy.
• alloys A to G alloys A to G
• comparative alloys H to J
• the alloys according to the invention for producing a shell of a casting roll achieve the desired recrystallized fine-grain structure with a correspondingly good elongation at break.
• a particle size of more than 1.5 mm is present, which reduces the plasticity of the material.
• the alloys A to G according to the invention again exhibit good elongations at break and a grain size of less than 0.5 mm, while the comparison alloys H to J have a coarse grain with a grain size of more than 1.5 mm and lower elongation at break values.
• these copper alloys have clear processing advantages in the manufacture of jackets, especially for larger casting rolls of two-roll casters, which makes it possible to produce a fine-grained end product with optimal basic properties for the application area.

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• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Continuous Casting (AREA)
• Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
• Extrusion Of Metal (AREA)
• Mold Materials And Core Materials (AREA)
• Rolls And Other Rotary Bodies (AREA)

Applications Claiming Priority (4)

Publications (3)

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• 2002
  • 2002-10-25 TW TW091124995A patent/TW590822B/zh not_active IP Right Cessation
  • 2002-10-28 CA CA2410245A patent/CA2410245C/en not_active Expired - Lifetime
  • 2002-11-05 MX MXPA02010879A patent/MXPA02010879A/es not_active Application Discontinuation
  • 2002-11-14 EP EP02025371.2A patent/EP1314495B1/de not_active Expired - Lifetime
  • 2002-11-14 US US10/294,357 patent/US20030094219A1/en not_active Abandoned
  • 2002-11-19 CN CN02151419A patent/CN1419982A/zh active Pending
  • 2002-11-19 BR BR0204713-6A patent/BR0204713A/pt not_active Application Discontinuation
  • 2002-11-20 NO NO20025563A patent/NO340437B1/no not_active IP Right Cessation
  • 2002-11-20 JP JP2002336609A patent/JP4295492B2/ja not_active Expired - Lifetime
  • 2002-11-20 KR KR1020020072434A patent/KR100961239B1/ko active IP Right Grant

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