I had to laugh when I saw the title of this thread.
We used to make tubing in a specialty stainless alloy.
How special? Well we bought the two heats of it that melted each year.
For specialty steels there are many small distributors.
Start with people like Alro and Fry, if they don't have it...
What is the tube material?
Condensing streams are tricky.
Often there will be impingement protection in the form of solid rods as the first two rows in place of tubes.
In main steam condensers they run some crazy velocities but they can spread it out a lot and provide protection.
If you simply wanted to cut the flange from plate you would use 140mm plate wouldn't you?
Isn't this the same orientation as his original solution?
But in this case the "LT" and "ST" very around the ring.
At least with his approach they will stay constant.
Is he cutting across the plate or along...
One of the problems with alloys like 91 is that you can't judge the creep strength of the welds based just on looking at them.
If you don't actually have data on the impact of weld repair (and re-PWHT) then caution is needed.
Overlapping HAZs are a rats nest of issues.
In some cases it doesn't matter.
In some alloys a little more heat isn't a bit deal, you test and make sure that it is OK.
But in alloys where there is precipitation it can be a nightmare.
Precipitates will grow and coarsen and this can seriously...
Any surface treatments?
17-4 will only get you in the low to mid 40's HRC.
With tool steels you are dealing with mid-50's into the low 60's.
What are you cutting?
How about virtually none.
https://nickelinstitute.org/media/1724/materialsforsalinewaterdesalinationandoilfieldbrinepumps_11004_.pdf
Unless this is oxygen free (<5ppm) and cold I don't see plain cast iron lasting in the velocity and turbulence of a pump.
You might be able to use a Best tester with some special fixturing.
but I am more with IR on this.
Measuring load (torque) may be your best option.
We had CNC lathes that had a carbon steel backing plate that was replaceable.
After every few pieces there was a cut taken from the edge of the...
dgee, we used to have to mix a very corrosive chemical into a blend.
We found a source for investment case Ni alloy mixers.
I can't imagine how a coated unit would be effective.
I did a lot of batten overlay once upon a time.
We welded solid strips of Ni alloy to the CS and then welded thin sheets of Ni alloy to the strips.
What a PIA.
The best way to see this to put a fine grid onto a flat tensile sample.
As you pull it your will see distortion of the grid at stress well below the Engineering Yield Stress.
This is small localized yielding.
As you get more yielding you will one area start to neck, and then that will slowly...
If they are the correct polymer my hunch is that the compounder changed some ingredients.
Different fillers (maybe just different brands) or different curative chemcials.
We used to have difficulty in hot water service because of issues like this.
Viton should work and EPDM or silicone should...
What are your clients rules about weld repair?
Commonly you would have to grind it out, then perform NDT to show that you are into sound metal, and then re-weld.