Von Mises Stress: Yielding & SF Criterion Equation

[xJJx]

Hi, just wanted to ask for the von Mises criterion equation, is the equation without the SF (the one I circled in blue) only applicable when yielding has FIRST occurred? (i.e when SF=1)? and is the equation including the SF (one I circled in orange) applicable to all cases? (i.e whether the material has yielded or not)
thank you

 

[xJJx]

sorry the images didn't upload on my original post: