90/10 CuNi Welding

Date 12-06-2010 12:25

Have any of you had some experience with this alloy (90/10 CuNi) we are looking at some fabrication work with pipe made out of these alloys?

Is this stuff expensive?

They say it sort of welds like stainless

By 99205

Date 12-06-2010 20:44

Try here, might help.
http://www.stainless-steel-world.net/pdf/12014.pdf

By Kix

Date 12-07-2010 17:34

Weldability is very nice, but different. It runs real dirty. The ERCuNi or ER(67) Filler rod is very expensive and so is the pipe it self. It does require more amperage then you would think to run even thin wall pipe. If you can weld stainless then you will take on to the CuNi pretty quick.

Kix

By TimGary (****)

Date 12-08-2010 14:52

The Navy uses a lot of 90/10 for piping systems.
IMHO, this stuff brazes very well and is a lot quicker than GTAW.

Tim

By Platinumbased (**)

Date 12-06-2010 23:37

Any welding rod containing NI will be very expensive. Monel, Iconel, Hastalloy, etc. Huge costs as spot metal prices for bulk NI is over $10/pound and CU is over $4/pound. Add in fabrication costs, etc and this rod or wire will be very expensive. Maybe $200 plus per 10 pounds of rod? I know in 2007 when NI was over $20 a pound, the price of Inconel rod was off the charts. The customer went nuts but what were to do? Buy it now as the price will only rise in the future. Stock it if you have the cash on hand. Inflation is coming and base metals are going to go through the roof very soon.

By Superflux (****)

Date 12-07-2010 03:13

Did some 95/5 way back when, all I can remember is that you had to really crank up the heat, and it did not feel like stainless to me. Also, lots of little "swirlies/contaminants" floating around in the puddle??? Fun stuff though...as in a relatively short term learning curve.

By welder5354 (**)

Date 12-08-2010 01:48

I welder a CuNI procedure a few months ago
I used 3/8 in plate. No landing, but the gap was very wide.
On one end the gap was 5/32 and on the other end it was 1/4 inch or more.
Plenty of heat was needed to get good penetration.
CuNi has a tendency to really draw together.
My procedure plate was about 12 in long, even then i had to put a bridge tack
in the middle of the joint to prevent it from closing too much.

By TRC

Date 12-17-2010 20:24 Edited 12-17-2010 20:44

Also use the crater fill option on your machine if it has one or back off slow with your foot pedal or there will be an indication at the creater, picked up by PT.

I also have approx. 20lbs of RN 60, 3/32, (tested to MIL-STD) for sale.