copper backing

[erfannehmet]

Hi
I work in spiral gas pipe production. We use copper backing for internal welding but we have a copper polution problem. Are there any persons who know good grade of copper with good abrasive resistance?

 

[metengr]

Copper polution problem??? Normally, I see copper chill blocks used to restore or reconstruct worn or damaged edges on steels. For groove welding where you want to establish full penetration, why don't you use steel strap for backing and remove it?

 

[stanweld]

If wear of the copper backing is the source of contamination, choose berrylium copper. If copper melting is the source of contamination, increase the mass of the copper backing or install water cooling of the copper backing, assuming that you cannot decrease welding current (decreased weld metal deposition and production).

 

[Duwe6]

+1 for switching to a water-cooled copper 'shoe'.

 

[erfannehmet]

Tkank you for your answering
we used copper bar with 99.9% Cu amd .0001% Be with HB=71.8 and have that problem. On the other hand we can not use copper grade with high hardness because of our equipment limitation.I wana know how many amount of beryylium should be needed for good result?

 

[EdStainless]

There are standard Be-Cu alloys out there in use.
These are water cooled, right?

Another option would be Be-Ni. Very expensive, good heat transfer and good electrical conductivity. Not as good as Cu but better than any other options.

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Plymouth Tube

 

[erfannehmet]

In your idia which one is better for backing?
Aluminium Bronze nickel or berrylium copper?

 

[stanweld]

Berrylium copper would be prefered. BeCu alloys contain 0.5% to 3% Be. Strength is accomplished by heat treating or heat treating and cold working.

 

[vanci]

Have you considered using ceramics?

 

[erfannehmet]

Thank you for your helping
As I said before we are producing spiral steel pipe by submerged arc welding and used copper backing for ID welding. we have copper taint on the OD surface for six month. At first we think these copper taints comes from the copper backing but copper density is more than iron so how copper can comes up and set at the surface of outer weld? Morover we use wire with copper coating. Is it possible that these copper taints comes from these copper coating when this coating flaking?

 

[vanci]

When during the manufacturing cycle do you see the copper appear? Is it direclty after welding is completed or after a different manufacturing step? I am doubtfull the copper is coming from the coating on the wire.

 

[erfannehmet]

Thank you for helping
These copper apear when we remove slag from outer weld.