17-4 stainless wheel rolling on 316 stainless flat bar
17-4 stainless wheel rolling on 316 stainless flat bar
(OP)
Howdy folks,
I'm working on a project that has a 16" diameter stainless steel wheel which I'm proposing to fabricate from 17-4 stainless rolling on a 316 stainless steel flat bar. Wheel loads are in the 45kN range. Client has raised the question of galling. Can anyone provide insight on this phenomenon and whether it will be a challenge in this instance. Application is a freshwater gate.
Thank you in advance.
I'm working on a project that has a 16" diameter stainless steel wheel which I'm proposing to fabricate from 17-4 stainless rolling on a 316 stainless steel flat bar. Wheel loads are in the 45kN range. Client has raised the question of galling. Can anyone provide insight on this phenomenon and whether it will be a challenge in this instance. Application is a freshwater gate.
Thank you in advance.





RE: 17-4 stainless wheel rolling on 316 stainless flat bar
There is enough hardness difference that galling shouldn't be bad.
You will dent the 316 with any significant load.
Combined with the risk of corrosion (esp on the 17-4 PH) you could end with a fairly bumpy track.
You might look to see if you can find Nitronic 50 bar to use in place of 316, and maybe you can find bar that has been cold rolled to higher hardness. The Nit 50 will also have better galling resistance.
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P.E. Metallurgy, Plymouth Tube
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
Nit 50 (S20910) is much more common, and does better than any of the 3xx alloys.
It is called XM-19 in ASTM and it is covered by a boatload of specs.
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P.E. Metallurgy, Plymouth Tube
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
Best regards.
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
What ranges of hardness does Nit 50 come in? I would suspect the cold rolled condition would offer higher hardness than the annealed state. Does the state modify the yield and ultimate strengths?
RE: 17-4 stainless wheel rolling on 316 stainless flat bar
It raises tensile strength (UTS and yield), hardness, galling limits, and lowers the ductility some.
In most cases material with roughly >100ksi min yield and a UTS over 125ksi will get you good performance without being too difficult to work with.
(as a note we cold draw 21-6-9, Nit 40 tubing for use in aircraft hydraulic systems, it is 140-160 UTS and it still have over 20% elongation)
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P.E. Metallurgy, Plymouth Tube
RE: 17-4 stainless wheel rolling on 316 stainless flat bar