A METHOD OF MANUFACTURING A GUIDE ROLLER, AND CORRESPONDING GUIDE ROLLER AND WIRE ROLLING MACHINE

Abstract

A method for manufacturing a guide roller for hot wire rolling includes the steps of providing a guide roller made of an Al alloy, the guide roller including a wire guiding surface, and applying a coating onto at least a part of the wire guiding surface by a metallic wire Direct Energy Deposition (DED) operation and/or a metallic powder DED operation.

Claims

1. A method for manufacturing a guide roller for hot wire rolling, the method comprising the steps of: providing a guide roller made of an Al alloy, the guide roller including a wire guiding surface, and applying a coating onto at least a part of the wire guiding surface by a metallic wire Direct Energy Deposition (DED) operation and/or a metallic powder DED operation.

2. The method according to claim 1, wherein the metallic wire and/or the metallic powder is any of a Ni based alloy, a Co based alloy or a Fe based alloy.

3. The method according to claim 1, wherein the step of applying the coating includes applying more than one layer by use of DED.

4. The method according to claim 1, wherein the step of applying the coating is done with a varied application speed.

5. The method according to claim 4, wherein the application speed is varied by decreasing the speed at least one time during application of the coating.

6. The method according to claim 1, wherein the DED operation is any of laser cladding, plasma transferred arc (PTA), electron beam melting (EBM) or selected laser melting (SLM).

7. A guide roller for hot wire rolling, the guide roller comprising: a guide ring made of an Al alloy, the ring having a wire guiding surface for receiving wire, and a coating covering at least a part of the wire guiding surface, the coating being applied by a DED operation.

8. The guide roller according to claim 7, wherein the coating is made of any of a Ni based alloy, a Co based alloy or a Fe based alloy.

9. The guide roller according to claim 7, wherein the coating has a radial thickness with a value of from 0.25 mm to 2 mm.

10. A wire rolling machine comprising a guide roller according to claim 7.

11. A wire rolling machine comprising a guide roller which has been manufactured by the method according to claim 1.

12. The method according to claim 2, wherein the Fe based alloy is a stainless steel.

13. The method according to claim 3, wherein the step of applying the coating includes applying 2-20 layers by use of DED.

14. The guide roller according to claim 8, wherein the Fe based alloy is a stainless steel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will hereinafter be further explained by means of non-limiting examples with reference to the appended schematic figures, where;

[0025] FIG. 1 is a cross-sectional view of a guide roller according to an example embodiment of the present invention;

[0026] FIG. 2 is a flowchart of a method according to an example embodiment of the present invention; and

[0027] FIG. 3 is a schematic view of a wire rolling machine comprising a guide roller according to an example embodiment of the present invention.

[0028] It should be noted that the drawings have not necessarily been drawn to scale and that the dimensions of certain features may have been exaggerated for the sake of clarity. Like reference numerals in the drawings refer to similar parts unless expressed otherwise.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0029] FIG. 1 depicts a cross-sectional view of a guide roller 1 according to an example embodiment of the present invention. The cross-sectional view is defined by a plane which extends along a rotational axis A of the guide roller 1. The guide roller 1 is made from an aluminium (Al) based alloy and comprises a wire guiding surface 2 to receive and guide a wire (not shown) to a certain position in the wire rolling machinery 4 (see FIG. 3). The wire guiding surface 2 in the shown embodiment has a concave shape, but it could also have any other shape, such as V-shaped, spherical or tapered shape depending on the requirements of a particular guide roller 1.

[0030] The guide roller 1 further comprises a coating 3 covering at least part of the wire guiding surface 2. The coating 3 has been applied to the aluminum guide roller 1 by means of a metallic wire Direct Energy Deposition (DED) operation and/or a metallic powder DED operation.

[0031] The coating 3 may be made from a material with high red hardness, such as Ni based alloy, a Co based alloy or a Fe based alloy mixed with Cr, such as a stainless steel. By red hardness is meant the ability of a material to retain the hardness and durability upon heating to red heat, i.e when the material turns red, typically >600 degrees Celsius for steel.

[0032] Other alloying elements in the coating 3 material to obtain high red hardness may further be any of tungsten, molybdenum, cobalt and vanadium.

[0033] The coating 3 thickness may preferably be from 0.25 mm to 2 mm, as seen in a radial direction of the guide roll. This to ensure enough protection of the aluminum guide roll from the hot wire, yet without consuming too much of the high performing and costly coating 3 material. By the radial direction is meant a direction which is perpendicular to and intersects with the rotational axis A of the guide roller 1.

[0034] FIG. 2 depicts a flowchart of a method according to an example embodiment of the present invention. The method is a method for manufacturing a guide roller 1, such as the guide roller 1 shown in FIG. 1.

[0035] The method comprises: [0036] S1: providing a guide roller 1 made of an Al alloy and comprising a wire guiding surface 2, [0037] S2: applying a coating 3 onto at least part of the wire guiding surface 2 by means of a metallic wire Direct Energy Deposition (DED) operation and/or a metallic powder DED operation.

[0038] The step S2 may be followed by a subsequent step of machining the applied coating 3, such as by grinding, honing or polishing the coating 3. This to form a finer surface structure, thereby reducing friction when receiving the wire.

[0039] Preferably, applying the coating 3 comprises applying more than one layer by use of DED, such as 2-20 layers.

[0040] Further, the application speed may be varied during application of the metallic wire material and/or metallic powder on the guide roller 1. For example, the speed may be varied by decreasing the speed at least one time during the application of the coating 3. Thereby, a thin layer may first be provided on the guide roller 1 using a relatively higher application speed, followed by one or more thicker layers as the application speed is reduced, until e.g. a final radial thickness of 0.25 mm-2 mm is obtained.

[0041] The wire guiding surface 2 of the guide roller 1 as shown in FIG. 1 has a varying radius, as seen in the cross-sectional view. In this embodiment, the radius is varying such that a concave outer profile is formed, i.e forming a groove having a shorter radial distance to the rotational axis A of the guide roller 1. As may be gleaned from FIG. 1, also the coating 3 may become thicker in the lower part of the groove. This may be due to relatively lower surface speed during the coating 3 application step compared to the portions at greater radial distance from the guide roller's 1 rotational axis A. According to an example embodiment, the rotational speed of the guide roller 1 during the application of the coating 3 is varied such that a constant surface speed is achieved. Thereby a coating 3 with a uniform thickness can be obtained.

[0042] FIG. 3 depicts a schematic view of a wire rolling machine 4 comprising a guide roller 1 according to an example embodiment and/or a guide roller 1 manufactured according to an example embodiment of the method as disclosed herein. It is to be understood that the wire rolling machine 4 may be any other machinery using guide rollers 1 to feed material in a similar fashion.

[0043] It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.