Mystery Alloys sold.... Cupronickel with no ANSI or otherwise....

[MERLIncMan]

Cupronickel - copper nickel alloys. Developed specifically for seawater heat exchangers, but have found welcome in the brake/fuel/transmission line hot-rodder types.
Apparently its malleability in tube form is between that of mild steel and soft copper.
Project *may* call for a coil of this stuff in 1/2" OD for... a seawater heat exchanger! (*Design subject to things that can actually be gotten)
I find some pretty good documentation regarding the corrosion resistance of different alloys of the stuff (seems to be based on the obvious ratio - 90:10, 70:30, etc)

The problem is that the people selling coils of it don't bother to put the alloy anywhere, just claim that it's copper nickel. That's like saying "made of plastic" - WHICH PLASTIC YOU DENSE @#%$%@!!!???

Grrr.

So, does anyone have any thoughts regarding a supply for 1/2" OD cupronickel tubing that can be made into a coil (thinking flared fittings) - and the company has the plane sense to, you know, say which cupronickel it is?

Thank you for your time!

 

[B2]

Hi, Clearly this is an issue that goes back a long time. So it has been studied a lot and published on a lot. To review the technical side of this try https://www.copper.org/applications...ion/corrosion_resistance_and_antifouling.html or web search "copper nickel alloys corrosion"

Copper and Nickel form a solid solution (phase diagram) which usually implies that their chemical and physical properties change uniformly as the ratio of material is varied. They are both face centered cubic crystalline materials and a solid solution means that the crystal structure does not change as the composition is varied.

Copper is soft, Nickel is hard. The more Nickel in the alloy the harder and more brittle, but the electrochemical potentials for preventing corrosion are better for Ni, hence the reason of making an alloy.

When working the materials, the final stress in the material, especially at bends etc. where work hardening has occurred, will commonly accelerate the corrosion process. Hence, sometimes parts are annealed after being made. web search "stress annealing copper nickel phase diagram" to gain knowledge about this. https://www.copper.org/applications/marine/cuni/properties/DKI_booklet.html

Good luck.

 

[mksj]

I think if you look for Monel Alloy is is specific type, the most common being the 400 which is more malleable, the K500 has a higher strength but more prone to stress cracks. Use to do some boat building decades ago, many of the heat exchangers used Monel , but do not recall using tubing. Monel tubing is carried by some metal vendors but expensive.

 

[MERLIncMan]

Hi, Clearly this is an issue that goes back a long time. So it has been studied a lot and published on a lot. To review the technical side of this try https://www.copper.org/applications...ion/corrosion_resistance_and_antifouling.html or web search "copper nickel alloys corrosion"

Copper and Nickel form a solid solution (phase diagram) which usually implies that their chemical and physical properties change uniformly as the ratio of material is varied. They are both face centered cubic crystalline materials and a solid solution means that the crystal structure does not change as the composition is varied.

Copper is soft, Nickel is hard. The more Nickel in the alloy the harder and more brittle, but the electrochemical potentials for preventing corrosion are better for Ni, hence the reason of making an alloy.

When working the materials, the final stress in the material, especially at bends etc. where work hardening has occurred, will commonly accelerate the corrosion process. Hence, sometimes parts are annealed after being made. web search "stress annealing copper nickel phase diagram" to gain knowledge about this. https://www.copper.org/applications/marine/cuni/properties/DKI_booklet.html

Good luck.

Much appreciated, thank you

 

[MERLIncMan]

I think if you look for Monel Alloy is is specific type, the most common being the 400 which is more malleable, the K500 has a higher strength but more prone to stress cracks. Use to do some boat building decades ago, many of the heat exchangers used Monel , but do not recall using tubing. Monel tubing is carried by some metal vendors but expensive.

Thank you for the information