SS to SS Friction Factor 1

[DSB123]

Hi All,
Does anyone in the community know of any references to friction factors for contact between Stainless Steel to Stainless Steel?

 

[kenvlach]

Friction factors for stainless on stainless are notoriously unreliable due to galling. I've seen the value of 0.3 used, but if the loading breaks through the invisible oxide film that makes stainless stainless, cold welding can occur. General rules are avoid like microstructure (e.g., austenitic on austenitic is worse than austenitic on ferritic or martensitic) and than the better the corrosion resistance the more an SS is likely to self-gall (due to thinner oxide). An even better rule is that the rules are unreliable, use actual testing.

Carpenter Technology has a very good handbook available called 'Carpenter Stainless Steels.' Pages 327-329 give threshold gallin stresses for various combinations of stainlesses. Their on-line site doesn't show the table in same form, but you can enter the particular stainless steel(s) to get the galling data. Under Technical, Properties, Wear Resistance. Same place gives 'Average Volume Loss-Abrasive Wear Resistance' data. Registration (free) required.

http://www.cartech.com/sao_products/

 

[EdStainless]

What finish? What lubricant? What load?
If there is little lube and much load then they will gall.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[Shmulik]

http://www.roymech.co.uk/Useful_Tables/Tribology/co_of_frict.htm

 

[koen31]

I can't answer the question, but maybe you find something usefull in one of my links ?

http://www.msm.cam.ac.uk/tribo/tribol.htm

http://docenti.ing.unipi.it/tribo/gruppoNEW.html#International

http://www.sait.co.za/

http://www-mech.eng.cam.ac.uk/Tribology/

http://www.msm.cam.ac.uk/tribo/links.htm

Koen

 

[DSB123]

Hi all,
Thanks for the responses. However the situation is a stainless steel pipe shoe (304) against stainless steel supporting steel (304). The loads are highish (greater than 40 KN with area of contact 37500 Sqmm) -there will be no lubrication.

Any other thoughts?

 

[JamesCKelly]

Consider making the support of Nitronic 60, if you can get the product form you need. This is the only commercially available stainless with decent galling resistance. N60 against itself is best, but even Nitronic 60 against 304 is a lot better than 304 against 304.
Would be nice to know something about the corrosive conditions, maybe even the metal temperature.