DE10321566A1 - Process for the production of a hollow body as a semi-finished product for a crucible or a casting roll - Google Patents

Abstract

The blank producing process involves casting a cylindrical block (1c) and forging and piercing it while it is radially supported, leaving a bottom. It is then spread by a mandrel and finally deformed by a drawing die (11) and a mandrel (10), producing the hollow body (12). All deforming stages take place under heat. With the block spread out, a bond (14) can be created on the hollow body.

Description

The The invention relates to a method for producing a cylindrical hollow body made of copper or a copper alloy as a semi-finished product for a crucible or a casting roll according to the characteristics in Preamble of claim 1.

A common one Process for producing a cylindrical hollow body as Semi-finished products for a crucible or a casting roller is composed of the steps of casting-punching-forging. First of all a continuously cast block compressed in the longitudinal direction. So that the block does not buckle when compressed, the maximum ratio is its Length too its diameter is about 3: 1. The compressed block then becomes help a piercing pin over his entire extension seen in the direction of upsetting perforated.

The perforated block is then heated again and in this 2nd heat Forge about a thorn widened. Depending on the circumstances, it must be properly expanded the perforated block in a 3rd heat if necessary be tempered again.

The The expanded block is then usually made by open-die forging to a hollow body formed with or without a flange, depending on whether from this In the end, a crucible or a casting roller is to be manufactured. In this context, it may be necessary to expand the to heat the perforated block several times in succession.

in the With regard to the fact that for a proper upsetting the cast block is only one length may have, which corresponds to approximately three times its diameter, to prevent the block from kinking, conditional use large Block dimensions only low degrees of deformation. Consequently, the attainable Material properties impaired.

On Another disadvantage in the known case is that during the Forging by the only locally acting forging forces inhomogeneous forming is generated. This results in losses in the theoretically achievable material properties.

Furthermore consists of repeated reheating when the perforated block is exposed and the risk of grain growth in long forging.

All in all is the known method due to the limited machining accuracy the provision of larger quantities of material connected which leads to that the so-called I / O ratio (Entry / discharge ratio) in the area above 4 lies. The economic output is therefore reduced.

The Invention lies - starting out from the state of the art - the Object of the task, a method for producing a cylindrical hollow body made of copper or a copper alloy as a semi-finished product for one Crucible or a casting roller to create a more economical application with improved material properties guaranteed.

This Task is with in the characterizing part of the claim 1 specified features solved.

by virtue of the fact that now both the upsetting of the cast Blocks as well as the punching are carried out with radial support of the block, can now be used a cast block that clearly has a smaller diameter in relation to its length. The buckling of the very slim block can, for example, in a pot-like Recording with an inner matrix can be prevented. This will not only higher, but also more uniform degrees of deformation reached. An overall smaller-sized block can also be used for forming to be provided.

With the process steps of widening by means of an expanding mandrel and stretching over one Drawing mandrel becomes an additional one Forming in the outer area reached the wall of the block and ultimately the hollow body, whereby the Create a fine grain structure favored becomes.

The hollow bodies manufactured in this way can then be in the usual Be further transformed into a crucible or a casting roller.

The Invention therefore creates the prerequisites for ensuring that the overall degree of deformation and homogeneity the forming due to the process steps punching the cylindrical Blocks with subsequent drawing presses can be significantly improved can. By the higher one dimensional stability there are also significantly smaller additions of lost material. The economy is increased significantly.

It is also part of the prior art to manufacture cylindrical hollow bodies as semifinished products for a crucible or a casting roll by rounding and longitudinal seam welding of sheets. Opposite the This method has the additional advantage that the material properties are homogeneous over the entire circumference of the hollow body.

As a general rule can be combined by expanding the block and stretching the Crystal orientation of the hollow body to be manufactured can be influenced that the grain structure is oriented in the longitudinal or transverse direction. So the grain orientation and thus the strength over this Be adapted to the main direction of stress. As a result, are especially in the case of hollow bodies produced casting rolls better service life to be expected.

The economic output is then further improved according to the invention, if according to claim 2 all forming steps in one heat carried out become. This procedure is due to the targeted combination Hole presses reachable with drawing presses. The deployment effort Thermal energy is significantly reduced in this way.

If according to claim 3 when stretching the expanded Blocks a bundle on the hollow body is generated, e.g. in that when the block is stretched it does not is completely moved by a drawing die, such offers Federal ideal for the welding of a flange, if ultimately from the hollow body produced a crucible is to be manufactured.

The The invention is explained in more detail below with reference to drawings. It demonstrate:

1 in the side view a cast cylindrical block;

2 in the schematic vertical cross section, a recording with a die for the block of 1 ;

3 in the schematic vertical cross section, the recording with the die when punching the block;

4 in the schematic vertical longitudinal section the expansion of the perforated block and

5 in the schematic vertical longitudinal section the stretching of the expanded block.

With 1 is in the 1 a cylindrical block made of SF-Cu, CuAg, CuNi or a precipitation hardening Cu alloy. The block 1 is continuously cast. The ratio of the length L to the diameter D is up to about 6: 1.

The block 1 according to 1 is according to the representation of the 2 into a die 2 used in one shot 3 located. The block 1 is shown in broken lines. The block is removed by an upsetting process in the direction of the arrow PF 1 changed in size. At the end of the upsetting process, the block has 1a the length L1 and the diameter D1. The die 2 prevents kinking of block 1 during upsetting.

According to the representation of the 3 is in the compressed block 1a a piercing pin 4 Pressed in centrally according to arrow PF1 and the block 1a perforated. The material of the perforated block 1b then rises between the inner wall 5 the die 2 and the surface 6 of the piercing pin 4 hollow cylindrical upwards. Punching in the direction of arrow PF1 is carried out on the punched block 1b a floor 7 remains.

The punched block 1b is then according to the representation of the 4 by means of an expanding mandrel 8th , which is moved in the direction of arrow PF2, with its inside diameter increasing from ID to ID1 and its outside diameter increasing from AD to AD1. The block to be expanded 1b is supported on an abutment plate 9 from.

After expanding the perforated block 1b becomes the expanded block 1c according to 5 with the help of a mandrel 10 in the direction of arrow PF3 through a drawing die 11 moves, the expanded block 1c to a hollow body 12 with floor 7 is ironed.

The stretching can be done so that the expanded block 1c not completely through the drawing die 11 is moved so that then at the free end 13 of the hollow body 12 A bunch 14 arises. This covenant 14 can be used to weld a flange.

All forming processes according to the representations of 2 to 5 are in the same heat, that is, the heat of the cast block 1 carried out.

Following the completion of the hollow body 12 according to 5 Depending on the requirements, this is further processed into a crucible or a casting roller.

1

block

1a

swamped block

1b

perforated block

1c

widened block

2

die

3

Recording f. 2

4

piercer

5

Interior wall v. 2

6

Surface v. 4

7

ground

8th

mandrel

9

Abutment plate

10

mandrel

11

die

12

hollow body

13

free end of 12

14

Covenant 13

AD

Outer diameter of 1b

AD1

Outer diameter of 1c

D

Diameter of 1

D1

Diameter of 1a

ID

Inner diameter of 1b

ID1

Inner diameter of 1c

L

Length of 1

L1

Length of 1a

PF

arrow

PF1

arrow

PF2

arrow

PF3

arrow

Claims (3)

Process for producing a cylindrical hollow body ( 12 ) made of copper or a copper alloy as a semi-finished product for a crucible or casting roll, in which a cylindrical block ( 1 ) cast this block ( 1 ) then compressed in the heated state in the longitudinal direction, then punched and finally using a mandrel ( 10 ) to the hollow body ( 12 ) is reshaped, characterized in that both upsetting and subsequent punching with radial support of the block ( 1 ) are carried out, with the perforated block ( 1b ) a floor ( 7 ) and that the punched block ( 1b ) in the inside diameter (ID) and outside diameter (AD) by means of a mandrel ( 8th ) expanded and ultimately the block thus expanded ( 1c ) over a thorn ( 10 ) by circumferential stretching to the hollow body ( 12 ) are reshaped. Method according to claim 1, characterized in that all forming steps are carried out in one heat. Method according to claim 1 or 2, characterized in that when the expanded block is stretched ( 1c ) A bunch ( 14 ) on the hollow body ( 12 ) is produced.