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US4134528A - Method of producing copper clad steel wire

06 Jan.,2025

USA - Method of producing copper clad steel wire

USA - Method of producing copper clad steel wire - Google Patents

Method of producing copper clad steel wire Download PDF

Info

Publication number: USA
Authority: US; United States
Prior art keywords: cross; steel wire; section; wire; annealing
Prior art date: -06-16
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Expired - Lifetime

Application number

US05/859,802

Inventor

Werner Bahre

Karl H. Stobaus

Gerhard Ziemek

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

KM Kabelmetal AG

Original Assignee

KM Kabelmetal AG

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

-06-16

Filing date

-12-12

Publication date

-01-16

-12-12 Application filed by KM Kabelmetal AG filed Critical KM Kabelmetal AG

-01-16 Application granted granted Critical

-01-16 Publication of USA publication Critical patent/USA/en

-12-12 Anticipated expiration legal-status Critical

Status Expired - Lifetime legal-status Critical Current

Classifications

- B&#;PERFORMING OPERATIONS; TRANSPORTING
- B23&#;MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K&#;SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K20/00&#;Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/22&#;Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded
- B23K20/227&#;Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded with ferrous layer

Definitions

the invention relates to a method of producing copper-clad steel wire, in which a copper strip fed longitudinally is formed around a continuously fed steel wire into a tube having a larger inside diameter than the outside diameter of the steel wire and is welded at its edges, and the sheath thus formed is drawn down onto the steel wire.
a method of this kind is known from U.S. Pat. No. 3,894,675.
the copper sheath surrounding the steel wire in this method is drawn down to the outside diameter of the steel wire to make a close fit, and is then heated to 850° C. in the continuous resistance annealing plant. At this temperature the wire is reduced in cross-section by at least 10%.
the present invention is directed to that of providing a method by which it is possible to provide steel wire with a firmly adhering copper cladding in a particularly economical manner.
the wire is reduced in cross-section by at least 30% by cold forming, i.e., at or near room temperature, thereupon annealed for at least three hours at at least 800° C., cooled slowly, and finally reduced in cross-section by at least 10%.
the cold forming of the wire with a reduction of at least 30% is intended to ensure firstly that the surface of contact between copper and steel will be enlarged, and secondly that any coatings of oxides or impurities existing on the surface of contact will be torn up by this drawing process, thereby improving the metallurgical bonding of the two metals.
the annealing at a temperature of at least 800° C. is expediently effected by a batch annealing process.
the slow cooling prevents the appearance in the steel wire of a martensitic structure, which would make a further reduction of cross-section difficult.
the cooling is effected to a temperature at or near room temperature, with the cooling time period generally being at least 4 hours.
the different materials diffuse into one another and at the same time are firmly metallurgically bonded to one another.
the surface of the clad wire, which was impaired by the annealing process, is thereby smoothed.
An optimisation of the process described above consists in that the wire is first reduced in cross-section by at least 50% in a plurality of drawing stages, thereupon annealed at from 830° C. to 870° C. for from three to four hours in vacuo or in an atmosphere of protective gas and slowly cooled in vacuo or in an atmosphere of protective gas, and finally reduced in cross-section by at least 30% in the cold state in a plurality of passes.
Annealing in vacuo or in an atmosphere of protective gas reliably prevents oxidation of the copper cladding and also the sticking of the wires, which are expediently wound into coils or on reels.
a steel wire which is in the form of a coil, and which has previously been drawn, soft annealed, pickled and neutralised, is first straightened in a continuous plant and cleaned by means of a number of sets of brushes.
a thin copper strip running continuously off a magazine reel is continuously formed by means of a forming tool into a slit tube round the continuously fed steel wire, the inside diameter of the tube being slightly larger than the outside diameter of the steel wire in order to avoid faults in the subsequent welding operation, in which the longitudinal edges of the copper strip are joined together by TIG welding.
the copper cladding is drawn down into firm contact with the steel wire by means of a drawing die, although it is not yet bonded to the steel core. The ratio between the diameter of the steel wire and the copper cladding determines the conductance of the clad wire.
This wire is preferably drawn down still further in a plurality of separate individual passes to provide a reduction in cross-section of at least 30%, and wound on special annealing reels or into loose coils.
the special annealing reels or the coils are introduced into a furnace and annealed at 850° C. in vacuo for 4 hours. The coils are then slowly cooled in the furnace.
the temperature prefferably kept constant for a few minutes at between about 350° C. and 500° C. in order to produce a sorbitic structure in the steel wire.
This sorbitic structure permits particularly easy forming.
the wire is drawn down to the final size (at least 10% reduction) in single or multiple drawing machines, depending on the grade of steel used. If reductions of cross-sections of more than 50% are necessary, the wires are additionally annealed at about 620° C. after a number of passes.

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Engineering & Computer Science (AREA)
Mechanical Engineering (AREA)
Metal Extraction Processes (AREA)
Heat Treatment Of Strip Materials And Filament Materials (AREA)
Wire Processing (AREA)

Abstract

Copper-clad steel wire is produced by forming a copper tube around the wire, and drawing down the copper tube and wire to reduce the cross-section of the wire by at least 30%. The wire is annealed, slowly cooled and the cross-section further reduced by at least 10%.

Description

The invention relates to a method of producing copper-clad steel wire, in which a copper strip fed longitudinally is formed around a continuously fed steel wire into a tube having a larger inside diameter than the outside diameter of the steel wire and is welded at its edges, and the sheath thus formed is drawn down onto the steel wire. A method of this kind is known from U.S. Pat. No. 3,894,675. The copper sheath surrounding the steel wire in this method is drawn down to the outside diameter of the steel wire to make a close fit, and is then heated to 850° C. in the continuous resistance annealing plant. At this temperature the wire is reduced in cross-section by at least 10%. With this known method difficulties occurred in obtaining a connection between the copper and the steel. The present invention is directed to that of providing a method by which it is possible to provide steel wire with a firmly adhering copper cladding in a particularly economical manner. In accordance with the invention, the wire is reduced in cross-section by at least 30% by cold forming, i.e., at or near room temperature, thereupon annealed for at least three hours at at least 800° C., cooled slowly, and finally reduced in cross-section by at least 10%. The cold forming of the wire with a reduction of at least 30% is intended to ensure firstly that the surface of contact between copper and steel will be enlarged, and secondly that any coatings of oxides or impurities existing on the surface of contact will be torn up by this drawing process, thereby improving the metallurgical bonding of the two metals. The annealing at a temperature of at least 800° C. is expediently effected by a batch annealing process. The slow cooling prevents the appearance in the steel wire of a martensitic structure, which would make a further reduction of cross-section difficult. In general, the cooling is effected to a temperature at or near room temperature, with the cooling time period generally being at least 4 hours. During the annealing process the different materials diffuse into one another and at the same time are firmly metallurgically bonded to one another. The following reduction of cross-section by at least 10% in the cold state; i.e., at or near room temperature, is intended to improve this bond still further and at the same time to reduce the thickness of the diffusion layer. At the same time the surface of the clad wire, which was impaired by the annealing process, is thereby smoothed. An optimisation of the process described above consists in that the wire is first reduced in cross-section by at least 50% in a plurality of drawing stages, thereupon annealed at from 830° C. to 870° C. for from three to four hours in vacuo or in an atmosphere of protective gas and slowly cooled in vacuo or in an atmosphere of protective gas, and finally reduced in cross-section by at least 30% in the cold state in a plurality of passes. Annealing in vacuo or in an atmosphere of protective gas reliably prevents oxidation of the copper cladding and also the sticking of the wires, which are expediently wound into coils or on reels. In order to eliminate aging which may occur during the last passes, it is advantageous for the wire to be relieved of stress by annealing after a number of passes. This stress-free annealing is advantageously effected at a temperature of at least 600° C. The invention will be explained more fully with the aid of an example of an embodiment thereof. A steel wire which is in the form of a coil, and which has previously been drawn, soft annealed, pickled and neutralised, is first straightened in a continuous plant and cleaned by means of a number of sets of brushes. A thin copper strip running continuously off a magazine reel is continuously formed by means of a forming tool into a slit tube round the continuously fed steel wire, the inside diameter of the tube being slightly larger than the outside diameter of the steel wire in order to avoid faults in the subsequent welding operation, in which the longitudinal edges of the copper strip are joined together by TIG welding. After the welding, the copper cladding is drawn down into firm contact with the steel wire by means of a drawing die, although it is not yet bonded to the steel core. The ratio between the diameter of the steel wire and the copper cladding determines the conductance of the clad wire. This wire is preferably drawn down still further in a plurality of separate individual passes to provide a reduction in cross-section of at least 30%, and wound on special annealing reels or into loose coils. The special annealing reels or the coils are introduced into a furnace and annealed at 850° C. in vacuo for 4 hours. The coils are then slowly cooled in the furnace. For this purpose it has been found expedient for the temperature to be kept constant for a few minutes at between about 350° C. and 500° C. in order to produce a sorbitic structure in the steel wire. This sorbitic structure permits particularly easy forming. After the annealing process, the wire is drawn down to the final size (at least 10% reduction) in single or multiple drawing machines, depending on the grade of steel used. If reductions of cross-sections of more than 50% are necessary, the wires are additionally annealed at about 620° C. after a number of passes. Numerous modifications and variations of the present invention are possible in light of the above teachings and, therefore, within the scope of the appended claims the invention may be practised otherwise than as particularly described.

Claims (5)

What is claimed is: 1. A method of producing copper-clad steel wire, comprising:providing a copper tube around a steel wire, said tube having an inside diameter larger than the outside diameter of the steel wire; reducing the cross section in the cold state by at least 30% followed by annealing at at least 800° C. for at least 3 hours, slow cooling and reduction in cross-section in the cold state by at least 10%. 2. A method according to claim 1, wherein the wire is first reduced in cross-section by at least 50% in a plurality of drawing stages, thereupon annealed at from 830° C. to 870° C. for from 3 to 4 hours in vacuo or in an atmosphere of protective gas, slowly cooled in vacuo or in an atmosphere of protective gas and finally reduced in cross-section by at least 30% in the cold state in a plurality of passes. 3. A method according to claim 2, wherein the wire is relieved of stress by annealing between the last passes. 4. A method according to claim 1 wherein the cooling is effected over a period of at least four hours. 5. A method according to claim 4 wherein the reduction is cross-section prior to annealing is by at least 50% and the reduction in cross-section subsequent to annealing is by at least 30%. US05/859,802 -06-16 -12-12 Method of producing copper clad steel wire Expired - Lifetime USA (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title DEA DEC2 (en) -06-16 -06-16 Process for the production of copper-clad steel wire DE -06-16

Publications (1)

Publication Number Publication Date USA true USA (en) -01-16

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Family Applications (1)

Application Number Title Priority Date Filing Date US05/859,802 Expired - Lifetime USA (en) -06-16 -12-12 Method of producing copper clad steel wire

Country Status (7)

Country Link US (1) USA (en) JP (1) JPSA (en) AU (1) AUB2 (en) BR (1) BRA (en) DE (1) DEC2 (en) GB (1) GBA (en) IN (1) INB (en)

Cited By (9)

* Cited by examiner, &#; Cited by third party Publication number Priority date Publication date Assignee Title USA (en) * -06-10 -04-11 Copperweld Corporation Method of cladding a steel core rod with another metal USA (en) * -03-31 -11-22 Sket Schwermaschinenbau Magdeburg Gmbh Method for producing a corrosion-resistant composite wire FRA1 (en) * -06-22 -12-24 Usui Kokusai Sangyo Kk Multi-wound stainless steel pipe USA1 (en) * -10-13 -04-13 Hobart Brothers Company Weld wire electrode for gas metal arc welding USA1 (en) * -03-22 -09-27 Commscope, Inc. Of North Carolina Methods for making aluminum clad copper wire CNC (en) * -11-27 -06-04 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#; Process of composite stainless steel / copper double metal rod CNA (en) * -03-25 -10-19 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#; A kind of production method for the oxidation Dumet wire that set copper pipe gas is burnt WOA1 (en) * -12-03 -06-11 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#; Reinforced steel wire for rubber hose, and production process thereof USB2 (en) * -03-30 -08-02 Hobart Brothers Llc Tubular wires made from copper coated strip

Families Citing this family (3)

* Cited by examiner, &#; Cited by third party Publication number Priority date Publication date Assignee Title FIC (en) * -04-02 -10-12 Outokumpu Oy COUPLING FOER LIVMODERINLAEGG SAMT FOERFARANDE FOER FRAMSTAELLNING AV DENSAMMA FRA1 (en) * -10-16 -04-23 Sumitomo Metal Ind Clad tube, bar or wire prods. mfr. - by inserting base metal blank in laminate metal tube, cold drawing and hot-forming CNB (en) * -09-10 -04-01 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#; Copper wire production line and manufacturing process thereof

Citations (3)

* Cited by examiner, &#; Cited by third party Publication number Priority date Publication date Assignee Title USA (en) * -05-28 -12-08 Phelps Dodge Copper Prod Method of making copper sheathed steel core cables USA (en) * -02-28 -08-26 Olin Mathieson Cylindrical or rod-like composite article USA (en) * -01-24 -07-15 Kabel Metallwerke Ghh Method and apparatus for making copper clad steel wire

Family Cites Families (2)

* Cited by examiner, &#; Cited by third party Publication number Priority date Publication date Assignee Title GBA (en) * -09-07 -03-06 Hitachi Cable Method of manufacturing composite metal wires GBA (en) * -01-13 -10-08 Olin Mathieson Process for Obtaining a Composite Metal Article

- -06-16 DE DEA patent/DEC2/en not_active Expired
- -09-21 IN IN424/CAL/77A patent/INB/en unknown
- -09-27 AU AU/77A patent/AUB2/en not_active Expired
- -11-21 BR BRA patent/BRA/en unknown
- -12-12 US US05/859,802 patent/USA/en not_active Expired - Lifetime
- -12-13 GB GB/77A patent/GBA/en not_active Expired
- -02-22 JP JPA patent/JPSA/en active Pending

Patent Citations (3)

Cited By (10)

* Cited by examiner, &#; Cited by third party Publication number Priority date Publication date Assignee Title USA (en) * -06-10 -04-11 Copperweld Corporation Method of cladding a steel core rod with another metal USA (en) * -03-31 -11-22 Sket Schwermaschinenbau Magdeburg Gmbh Method for producing a corrosion-resistant composite wire FRA1 (en) * -06-22 -12-24 Usui Kokusai Sangyo Kk Multi-wound stainless steel pipe CNC (en) * -11-27 -06-04 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#; Process of composite stainless steel / copper double metal rod USA1 (en) * -10-13 -04-13 Hobart Brothers Company Weld wire electrode for gas metal arc welding USB2 (en) -10-13 -12-10 Hobart Brothers Company Weld wire electrode for gas metal arc welding USA1 (en) * -03-22 -09-27 Commscope, Inc. Of North Carolina Methods for making aluminum clad copper wire CNA (en) * -03-25 -10-19 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#; A kind of production method for the oxidation Dumet wire that set copper pipe gas is burnt USB2 (en) * -03-30 -08-02 Hobart Brothers Llc Tubular wires made from copper coated strip WOA1 (en) * -12-03 -06-11 &#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#;&#; Reinforced steel wire for rubber hose, and production process thereof

Also Published As

Publication number Publication date BRA (en) -06-05 GBA (en) -08-22 AUA (en) -04-05 INB (en) -03-21 JPSA (en) -01-19 DEA1 (en) -01-04 DEC2 (en) -12-18 AUB2 (en) -05-22

What Are the Applications of CCS Tracer Wire

Copper clad steel (CCS) tracer wire combines the strength of steel with the conductivity of copper, making it a good choice for locating, pulling, and pipe bursting.

KLS supply professional and honest service.

But what is CCS wire, how is it different from other types of tracer wire, and where is it used?

What is CCS Wire?

Copper clad steel is made by metallurgically bonding copper cladding to a steel core conductor using high heat and pressure. The result is a high break load tracer wire that can still carry a current for location purposes.

To prevent damage, manufacturers also apply high molecular weight polyethylene (HMWPE) or high-density polyethylene (HDPE) insulation. The result is a direct burial rated wire with abrasion, crush, and water resistance.

CCS wire has several types, including high strength (HS), extra high strength (EHS), stress relieved (SR), and pipe burst. The strength needed for the job depends on the break load you need.

For example, you wouldn&#;t use solid copper tracer wire for pipe bursting because it would easily break.

What Makes CCS Tracer Wire Different

Compared to solid or stranded pure copper options, copper clad steel has several advantages.

Powerful Metal Combination

Steel is a strong alloy, giving the wire high tensile strength for drilling and pipe-bursting projects. The copper used to coat the steel core is highly conductive, making it easy for signals to pass through the cable.

Although other metals and alloys might be as strong or stronger than steel, they aren&#;t as cost-effective. Additionally, though aluminum is lighter than copper, it isn&#;t as conductive. More aluminum is needed to achieve the same conductivity, increasing gauge size.

More Cost-Effective Than Pure Copper

Steel is less expensive than copper, so it makes sense that CCS would be less costly than pure copper tracer wire.

The lower cost does come with a drawback, though. CCS isn&#;t as flexible as copper, making it harder for workers to manipulate.

CCS is Theft-Resistant

How often do we read about copper thieves breaking into homes, businesses, and construction sites to steal copper?

Copper is valuable, making it an attractive target. But steel &#; not so much. If a thief wanted to take CCS wire from a job site, it has little resale value at scrapyards. The steel core is also difficult to cut through using regular cutting tools.

Common Applications

Copper clad steel tracer wire comes in handy for many applications beyond locating underground utilities.

You can easily find CCS wire used across many projects, including the developing renewables industry.

Water and Sewer Pipe Applications

CCS wire can locate underground water and sewer pipes, but it also works well for grounding.

Are you interested in learning more about copper clad stainless steel sheets? Contact us today to secure an expert consultation!

When used as a grounding wire, copper clad steel safely reroutes electricity during a surge or fault. As a result, workers face fewer shock risks.

Code enforcement may also require grounding systems as part of an installation, so check before starting your project.

Directional Drilling and Boring

Thanks to its steel core, CCS has more tensile strength than pure copper tracer wire.

Crews can attach copper clad steel wire to drill bits used for directional drilling to track the bit&#;s location as it digs. Because the bit is easier to find, drilling projects are more accurate with fewer risks to other underground assets.

Although CCS isn&#;t as strong as pipe bursting wire, it works well for lower break load projects where strength isn&#;t critical to the job.

Open-Cut and Pipe Bursting

Open-cut installation is the most common way to install pipes, cables, and underground assets.

When costs are a concern, open-cut projects tend to be less expensive per linear foot than other methods. Workers also have direct access to the utility, allowing them to precisely position the tracer wire.

For pipe bursting, workers connect a wire to a bursting tool. A machine then pulls the tool through the old pipe to break it. This work often requires a high break load, meaning standard copper or stainless steel options aren&#;t up to the task. CCS wire can withstand the machine&#;s pulling power without stretching or breaking.

Other Applications

Copper clad steel has many other applications beyond water and sewer projects.

Gas Utilities &#; CCS tracer wire can locate underground gas lines. The wire is also good for bonding and grounding purposes.

Buried Conduit Projects &#; Tracer wire is common for many underground tracing projects, and CCS is no different. It does the same thing as solid copper tracer wire at a more economical price.

Wind Farms &#; In some cases, CCS can have special corrosion-resistant insulation and jacketing applied for offshore wind projects.

Overhead Ground Wiring &#; CCS is great for grounding, as its copper layer allows current to safely flow through it. The steel core also helps with vibrations.

Messenger Wire &#; Although messenger wires don&#;t carry current, they are critical in overhead electrical installations. These wires support other overhead cables, preventing them from sagging.

Horizontal Directional Drilling &#; Copper clad steel&#;s break load makes it a good option for lower-resistance drilling projects. For pipe bursting, a bulked-up CCS wire with a 4,700 lb. breaking strength is used.

Every Project is Different

It may seem like copper clad steel can do it all, but it&#;s best to understand the project&#;s full scope before jumping in.

Research the application, learn what APWA-approved color(s) you&#;ll need, and what the environment is like. Every installation is different, and sometimes a particular wire doesn&#;t check all the marks or may be overkill. The environment and final installation location will also dictate any special attributes the wire&#;s insulation or jacketing may need.

Teams should also see if there&#;s a need for cost-effective options. Solid copper tracer wire can become expensive for extended runs, making CCS a worthy replacement.

For more information, please visit copper composite material.

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