Fatigue data for 4140 steel?

[kjelliva]

Does anyone know where I can find a Wöhler-curve (S-N curve) for this material:

http://www.matweb.com/search/SpecificMaterial.asp?bassnum=M414BM

Primarily I'm interested in R=-1 and R=0 curves, but any help is greatly appreciated.

 

[metengr]

You might want to try here for starters.

http://www.fatiguecalculator.com/

 

[metengr]

You also might want to try this web site. I have used it before and you can register for free. It contains an excellent database on mechanical (including fatigue) properties for various carbon and low alloy steels;

http://barsteelfatigue.autosteel.org/login_bar.asp

 

[kjelliva]

I've tried that page, but the data they're operating with on this specific material can't be right. According to the material property finder, the material har Su lower than Sfl. This can't be right?

 

[kjelliva]

THe reply was for the fatigue calculator. I will try the other option. Thanks.

 

[metengr]

According to the material property finder, the material har Su lower than Sfl. This can't be right?

In this specific case, there is a published or test value that was used instead of a default value (like fatigue strength= 0.5 * UTS). Certain metals can exhibit hardening or softening behavior under cyclic loading versus monotonic loading conditions.