Hello Louie,
Are you using Fatigue Tool? Here you can see how Fatigue Strength Reduction Factor Kf is inserted in Fatigue tool https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v232/en/wb_sim/ds_Fatigue_Options.html?q=Stress%20Reduction%20Factor
Kf is a user input and can be found in various design handbooks. Once determined you can input Kf, which is refer to as Fatigue Strength Factor, under details view for the fatigue tool.
It takes into consideration material properties such as corosive environment, surface conditions etc and is found in bibliography. Ansys cannot calculate this factor for you.
You are navigating away from the AIS Discovery experience