Magnetic Corrosion Resistant Alloy Selection
Magnetic Corrosion Resistant Alloy Selection
(OP)
Looking for an upgrade to PH stainless which is more corrosion resistant (down hole conditions), stronger, and easily weldable (autogenously). Basically, I'd like a magnetic version of MP35N. Ideas??? I've looked at some of the duplex alloys and strength and weldability are of concern.





RE: Magnetic Corrosion Resistant Alloy Selection
http://www.questek.com/ferrium-s53.html
RE: Magnetic Corrosion Resistant Alloy Selection
In order to get good strength and control phases at higher alloy content you end up going to an austenitic matrix.
And then they are non-magnetic.
Calling any age hardening alloy weldable is a stretch, you have to assume that you will re-anneal and age after welding. Or that you will weld with an austenitic filler and live with much softer welds.
How much more corrosion resistance do you need?
How magnetic do you need it?
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Plymouth Tube
RE: Magnetic Corrosion Resistant Alloy Selection
RE: Magnetic Corrosion Resistant Alloy Selection
However if he has only been using 17-4 then 15-7 might be an option.
C450 has rather unimpressive corrosion resistance.
C465 is better, but not quite weldable.
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Plymouth Tube
RE: Magnetic Corrosion Resistant Alloy Selection
15-7PH is semi-martensitic, the austenitic would degrade the magnetics.
RE: Magnetic Corrosion Resistant Alloy Selection
Unless someone is still making AM350, it would be a little better.
Yes, C450 may be the easiest to work with and the best corrosion resistance. C465 is a pain unless you are dealing with very light sections.
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Plymouth Tube
RE: Magnetic Corrosion Resistant Alloy Selection
RE: Magnetic Corrosion Resistant Alloy Selection
RE: Magnetic Corrosion Resistant Alloy Selection
The advantage of solid state joining processes is that the material at the weld interface is only heated to a plastic state, and does not undergo the phase change from solid-liquid-solid that a fusion weld involves. So the microstructure of a solid state weld is much closer to that of the basis material than that existing in a fusion weld.
RE: Magnetic Corrosion Resistant Alloy Selection
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Plymouth Tube
RE: Magnetic Corrosion Resistant Alloy Selection
Or does he merely need the final assembly to be able to be picked up by an external magnetic field?
RE: Magnetic Corrosion Resistant Alloy Selection
With the iron based age hardening materials they become more magnetic as you age them.
Some (such as 17-7PH) are non-magnetic when annealed and very magnetic when aged.
Others are at least weakly magnetic when aged and the very magnetic when aged as well.
After the anneal you would age the material to the desired strength level.
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Plymouth Tube
RE: Magnetic Corrosion Resistant Alloy Selection
RE: Magnetic Corrosion Resistant Alloy Selection
You can't get that high of Cr without going to an austenitic structure.
Of course calling MP35N weldable is a stretch of that term. When you autogenous weld aged hardened alloys you get the worst of both worlds. A brittle weld and a very low strength HAZ, but if it works I won't argue.
Either go with a high strength steel and give up corrosion resistance (Ferrium M54), or stay with what you have.
So why do you need more strength? Tensile loading? It can't be because of exterior pressure, because strength does not help with crush resistance.
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Plymouth Tube
RE: Magnetic Corrosion Resistant Alloy Selection