FR2580525A1 - PROCESS FOR MAKING PASSING SHELLS FOR CONTINUOUS CASTING MACHINES - Google Patents

Abstract

A.PROCEDE TO REALIZE PASSAGE SHELLS FOR CONTINUOUS CASTING MACHINES. B. PROCESS CHARACTERIZED IN THAT BEFORE HEAT HARDENING, A COLD CONFORMATION OF THE SHAPED PART IS CARRIED OUT WITH SIMULTANEOUS CALIBRATION OF THE WALLS GIVING THE SHAPE BY MEANS OF A CHUCK 2 INTRODUCED IN THE SHAPED PART. C. THE INVENTION RELATES TO METHODS FOR REALIZING PASSING SHELLS FOR CONTINUOUS CASTING MACHINES.

Description

me- "Process for making passing shells for

continuous casting machines. "

  The present invention relates to a method for producing passing shells for cutting machines.

  continues from pieces of shapes made by

  pressing and / or drawing, and / or forging in curable copper alloys, in which process these shaped parts are first subjected to a homogenisation annealing, then quenched and then the material

cuprous is hardened by heat.

  It is already known (DE-OS 26 35 454) to use

  As the material for continuous casting shells of curable copper alloys, in which case, by suitable choice of the constituents of the alloy, such as chromium and zirconium, high values are obtained for the thermal conductivity, the resistance to heat as well as creep resistance and for hot plasticity. The shell plates made from such hardenable alloys are then annealed.

  homogenization at 103000 C, then quenched with water and

  end hardened at 475 C, machining with removal of

  chips from the plate to its final dimensions being

continued.

  These known process steps can also be used analogously for the production of tubular-shaped, thick-walled, one-piece shells, when the tubular form is formed by pressing, drawing, or other methods, the hardening treatment is carried out and thereafter

  final machining with chip removal is performed.

  The process steps proposed above are however not applicable under these conditions in a known process, in which to make straight passage shells but especially passing shells

  curved, conical or partially conical, a man-

  drin with internal final dimensions and the internal shape of the shell to be made is introduced into a section of copper tube and then this pipe section is pressed by cold deformation on the mandrel (DE-PS

18 09 633).

  The object of the invention is therefore to find a possibility of also making passing shells of hardenable cuprous materials so that these shells satisfy with regard to their quality.

the current requirements.

  This object is achieved in accordance with the invention in that, prior to heat-hardening, a cold forming of the shaped part is carried out with simultaneous calibration of the shape-forming walls by means of an introduced mandrel. in the form room. So he is

  appeared as a remarkable effect that, because of the conformity

  cold and calibration with a mandrel

  and the internal shape of the shell, it does not occur

  no deformations of the shell thus made when

  that it was then subjected to heat treatment in order to harden the cuprous material. As a result, the continuous casting shells made in this way have, even after very long periods of casting,

  very high dimensional stability with reduced wear.

258052-5

  3.- Cold conformation and calibration at

  a mandrel can be done in different ways.

  This is how the mandrel and the form piece can be

  moved at the same time through a matrix. In this context

  text has already (DE-PS 18 09 633) introduced in a rectilinear piece (tube section) a curved mandrel having the internal end dimensions and the shape of the shell to be made, and whose external dimensions are only a little less than or greater than the internal dimensions of the shaped part, whereby this piece of shape is preformed correspondingly to the dimensions

  chuck. Then, the form piece and the mandrel are

  together through a matrix to press closely

  the inner surfaces of the pipe section on the man-

  drin. Finally, the mandrel is removed from the shaped part

now cold stabilized.

  Another advantageous possibility is to perform the cold forming and calibration by efforts applied to the outer walls of the room

  in shape through a forging or welding process.

  Other suitable methods for shaping, are

  explosive processes, as well as hydrostatic processes

  ticks and electrodynamics. For special applications it has proved advantageous to combine two or more of the possibilities thus indicated. Thus, for example, after the simultaneous

  chuck and piece of form through a die;

  if after cold forming by forging or rolling, provide for the completion of the application

  by detonation of an explosive substance.

  The homogenization annealing of the shaped part before the cold forming and the calibration can be carried out in air, in which case the surfaces of the shaped part must then be subjected to a cleaning or smoothing process, for example by grinding. It may therefore be 4.- more advantageous to proceed with annealing.

  homogenisation of the whole piece of tubular shape.

  or only of its internal space in a

  reductive atmosphere. This is effected, for example, advantageously

  filling with dry charcoal,

  dull piece of form that is closed at both ends.

  mitted by perforated plate covers.

  In practice, we can implement for the

  embodiment of the invention, all hard copper materials

  cissables, for which during the steps of annealing and homogenization, cold forming and hardening, properties are obtained that allow their use as shell materials. These cuprous materials are, for example alloys based on uOur, OuCrZr,

  OuCoBe, OuCoNiBe, OuOoNiBeZr, CuNiSi etc. The materials

  curable cuprous crystals which can find an application

  cation which is advantageous during the practice of the invention, are, for example, alloys of 0.02 to 1.2% of chromium,

  0.05 to 0.4% zirconium, up to 0.04% lithium, calcium

  magnesium, silicon or boron as deoxidizing means, the remainder being copper and common impurities. The invention will be explained in more detail with reference to FIGS. 1 to 7 and taking as an example a

tubular shell curved.

  The reference numeral 1 denotes a tube section of any cross-sectional shape, made by spinning and / or by drawing and / or forging, and which consists of a curable copper alloy, for example of composition , 5% chromium, 0.12% zirconium 0.015% boron, the remainder being copper and impurities

  common. This section of tube 1 is first and foremost

  subject to homogenisation annealing in an atmosphere

  reducing temperature at 1000 - 1020 0C for about half a

hour and then soaked in water.

  e.- In the rectilinear section of tube 1, but

  possibly also pre-curved, we then introduce the man-

  Drin 2 coated for example a hard chrome plating and then the tube section is formed on the mandrel 2 by applying external forces, for example by a simultaneous passage through a matrix or by one or more processes

  forging or rolling. The cold conformation of the

  example, the initial hardness of about 55 DB is raised to 80

100 Brinell hardness.

  The mandrel 2 can, for the adaptation of the shell to be made to the circular shape of continuous casting installations, be already curved, possibly it

  may also be conical or partially conical

  than. When introducing such a mandrel into the trunk

  of a straight tube, preforming is already

  corresponding shell tube. Of course, the

  1 can already be brought to the curved shape during an additional operation, before introducing

also a curved mandrel.

  As a rule, after removal of the man-

  2 of the tube section 1, the shell tube already having a precise rating is heat-cured for about 3 to 4

  hours within temperature limits of 460 C0 to 480 C0.

  Advantageously, this heat treatment will also be carried out

under protective gas.

  For the indicated copper alloy, the following values can be obtained with the process according to the invention for a tubular shell: Thermal conductivity 324 (W; mK) Recrystallization temperature 700 (C0) Softening temperature 500 (OC) Hardness 2.5 / 62.5 DB. 142 Tensile strength 445 (N / mm2) Elongation limit 0.2 360 (N / mm2) 6.- Elongation DB fracture 18 (%) Heat resistance at 20000 416 (N / mm2) Elongation DBrupture at 200C00 17 (%) Hot resistance at 3500C 352 (N / mm2) Elongation DB rupture at 35000 (%) On the other hand, the values for a non-calibrated and cold-formed shell of the same alloy composition are as follows : Thermal conductivity 315 (W / mK) Recrystallization temperature 700 (C0) Softening temperature 500 (OC) Hardness DB 2.5 / 62.5 115 Tensile strength 375 (N / mm2) Elongation limit 0.2 282 (N / mm2) Elongation DB Breaking 19 (%) Resistance to HW at 2000C 345 (N / mm2) Elongation DB Breaking at 200 0 16 (%) Heat Resistance at 3500 285 (N / mm2) Elongation at Break- 35000 14 (%) The embodiment leaves open the question of the cross section of the shell. AT

  round cross sections, square, rectangular,

  polygons of known type, one can of course choose

  in any other cross-section, for example T-shaped or double-T cross-sections,

  provided only that mandrel 2 has the shape of sec-

  cross-section. Figures 6 and 7 show

  such embodiments.

7.-

RE V E N D I C A T I 0 N S

  1. A process for producing passing shells for continuous casting machines from shaped articles made by press-spinning and / or drawing, and / or by forging in curable copper alloys,

  die in which these pieces of shapes are first of all

  homogenized annealing, then quenched and then

  subsequently the cuprous material is heat-hardened, characterized in that prior to heat-hardening, the shaped part is cold-formed with simultaneous calibration of the shape-giving walls.

  by means of a mandrel introduced into the shaped part.

  2. A process according to claim 1, characterized

  in that the cold conformation and the calibration are

  by the simultaneous passage of the mandrel and the

  piece of shape through a matrix.

  3. The process according to claim 1, wherein

  characterized in that the cold conformation and the calibration are effected by means of forces applied to the outer walls of the shaped part during a process of

forging or rolling.

  4. The process according to claim 1, wherein

  characterized in that the cold conformation i and the calibration are effected by means of forces applied to the outer walls of the shaped part by detonation of a substance

  explosive or by an electro-dynamic process.

  5. A process according to claim 1, characterized

  characterized in that the cold conformation and the calibration

  hydrostatic pressure or

hydrostatic yield.

  6. Process according to any one of the

  2 to 5, characterized by the combination of process steps of passing through the die, forging

  or rolling with to finish a calibration by detonation

explosive substance.

  7. Process according to any one of the

  1 to 6, characterized in that the homogenous annealing

  at least the inner zone of the tubular shaped part.

  The shape is given in a reducing atmosphere.

  8. Process according to any one of the

  1 to 7, characterized in that the material used is

  curing copper alloys, an alloy of 0.2 to 1.2% chromium, 0.05 to 0.4% zirconium, up to 0.04% of one or more of the phosphorus elements , lithium, calcium, magnesium, silicon or boron as deoxidizing means, the remainder being copper and common impurities. 9.- Tubular shell for installation

  continuous casting carried out according to the corresponding process.

  in any one of claims 1 to 8, shell

  characterized in that it comprises a transverse section

  rectangular, polygonal and round.

  10.- Tubular shell for installation

  continuous casting carried out according to the corresponding process.

  in any one of claims 1 to 8, shell

  characterized in that it comprises a cross-sectional shape in T, double T, U or in L. It.- Tubular shell according to any one

  claims 9 or 10, characterized in that the sur-

  internal faces delimiting the hollow space, extend

  only partially or conically.