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S N Curves

S N Curves

S N Curves

Any one have the S Curve for ferrium 61.
And AISI 9310


RE: S N Curves


Attached is some old AGMA 411.02 data of root stress & contact stress vs load cycles for grade 2 aircraft spur/helical power gears. Suitable for carburized AMS 6265 (VIM-VAR 9310).

There is not much published fatigue data for Ferrium C61/C63/C64 alloys, since they are a fairly recent development. You can try downloading a datasheet for C61 from the Carpenter Technology website. It might include some limited tensile fatigue data.

Hope that helps.

RE: S N Curves

Thanks Terry

So if I may ask in the US what is the
Fatigue limit you are using..
The tables above are help full.

RE: S N Curves


My experience is mostly related to aircraft drives. For flight critical gears AMS 6509 (VIM-VAR C64) is now commonly used primarily for its high tempering temperature, which provides excellent performance in a loss-of-lube condition. The material is vacuum carburized (AMS 2759/7) and direct high-pressure gas quenched. Another benefit of C64 is its greater core strength vs X53/9310. Here is a paper that provides some limited bending fatigue data for C64.

The AGMA gear data I posted is suitable for carburized double-vacuum-melt quality 9310. To determine what value to use, you need to calculate your bending and contact stress levels at a specific load and number of cycles. This single composite load/cycle value is usually calculated using Miner's rule based on a load or mission spectrum.

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