Stainless Steel to Stainless Steel Friction Factors

[DSB123]

Hi All,
I am looking for a reference for Coefficients of Friction for the case of Stainless Steel to Stainless Steel (in the dry, unlubricated condition) Type 304. I know there are plenty of references for steel to steel but I need SS/SS. Anyone know of such a reference where values are given?

 

[RPstress]

No 304/304, but some limited data:

Extract from page 33 of Nitronic 60 brochure by High Performanced Alloys, see website

http://www.hpalloy.com

.

Adobe Acrobat text copy:

Table 54
Dynamic Coefficient of Friction
[tt] Test Stress Level, N/mm2
5.6 14.0 28.0 56.0 112.0
Alloy -------------------------------------
NITRONIC 60 .35 .38 .44
Stellite 66 .60 .63 —
NITRONIC 32 .45 .53 .65 .58

*Tested in water at 20°C, self-mated.

Table 55
Dynamic Coefficient of Friction
Ring on Block (15-45Ibs [67-200 N])*
Ring Block Coefficient of Friction
Type 440C NITRONIC 60 0.4 in Argon
0.4 in Air
Type 440C Type 304 0.4 in Air
Type 440C Type 316 0.5 in Air[/tt]

*Taken from: "Friction, Wear, and Microstructure of Unfubricated
Austenitic Stainless Steel," by K. L. Hsu, T. M. Ahn, and D. A. Rigm
Ohio State University. ASME Wear of Materials-1979.


However, 304 on 304 will gall at low stress (maybe a couple of ksi according to Armco). This will massively increase "friction" forces.

 

[EdStainless]

I have always used 3ksi as a galling limit for 304 or 316. At that point you are trying to weld the parts together.
Self mating is a poor practice, in stainless it is a disaster.
At the low loads that are possible with stainless the friction factors will not vary a lot based on material. Values in the range of 0.4-0.5 will almost always fit.

= = = = = = = = = = = = = = = = = = = =
Still trying to help you stop corrosion.
formerly Trent Tube, now Plymouth Tube
eblessman@plymouth.com
or edstainless@earthlink.net

 

[kenvlach]

From Carpenter Stainless Steels, page 329:
Threshold Galling Stresses, self mated, unlubricated ground finish
Annealed 304 (their Project 70): 8.0 ksi [55 MPa]
Cold drawn 304 (their Project 70): 2.5 ksi [17 MPa]

 

[DSB123]

All,
Thanks very much for the responses. The responses were what I expected especially about the galling problem. The situation is that we have stainless steel pipe shoes which sit on stainless steel support steel. I am concerned about the friction/stiction between the "like" materials. Any further thoughts?

 

[EdStainless]

What temperature? Hotter is worse.
Are these exposed to weather?

= = = = = = = = = = = = = = = = = = = =
Still trying to help you stop corrosion.
formerly Trent Tube, now Plymouth Tube
eblessman@plymouth.com
or edstainless@earthlink.net

 

[DSB123]

Hi EdStainless,
The temperature is around ambient (20 Deg C) and they are not subject to weather.

 

[Shmulik]

A previous discussion of this subject:
thread330-180155