Weld Repair of Non-Magnetic Steel

After looking at the data sheet supplied by Roadrunner, I'd suggest using inconel 625 filler. It should be compatible with the material. I would first determine the effect of welding on the parent material and I would be cautious if the gouge is large and requires a significant amount of filler. Usually damage to a seal surface is small and minor so a reapir should be of little consequence as it relates to changing the chemistry or strength of the parent material.

I would suggest welding the entire shoulder and remachining would be best to eliminate any possibility of distortion from welding. There is no way you are going to be able to weld it without it moving on you. In fact I would suggest that you probably should overlay the entire thread and have the thread remachined. Tubular products distort badly and threads of that nature have very close tolerances. it would not due if the part went egg shaped on you and you tried to make up the threads. you'll gall the hell out of it.

Inconel 625 is pretty much the most corrosion resistant material you could go back in with. It is basically the standard by which all other downhole materials are compared for corrosion resistance and it is definitely non-magnetic, But after looking at the Jorgenen spec sheet, you do realize that the yeild of Inco 625 is significantly lower than the parent metal don't you? (about half.)

I would strongly suggest you contact Jorgensen and find out what they recommend for weld repair filler. They may tell you it is non-weldable due to the large amount of Nitrogen in the alloy and the amount of cold work required to achieve the strength. The only repair option might turn out to be a thread recut if the part has enough excess length to allow for a recut. Many machine shops can do a recut while losing only an inch or two of length. if the design can accept the lost length, that would be my recommended repair option.

I would suggest that if welding is the only repair option available you should contact someone like Acute Technological Services here in Houston for advice. They are probably one of the leaders in welding oddball stuff, and are very familiar with downhole alloys and equipment.

Great responses from all...much appreciated!