Cast Iron Allowable Hertzian Stress

[mattyjb88]

Hi All.
I am working with a problem of a cast iron wheel rolling on a cast iron track (two different grades). This problem is well defined for steel materials, but I have not tackled it before with cast iron. This is an old 1950's piece of equipment. My gut feel is that the allowed hertzian stress is different for cast iron than steels, but I cannot find a reference confirming this or indicating how to go about it.

Can anyone indicate a reference for this or set me straight?
Cheers

 

[dgeesaman]

I would refer to cast iron gearing design standards if nothing else arises.