# The Bauschinger effect

I have a question on the Bauschinger effect. Let's say that we have a material with yield stress $400 \,\mathrm{MPa}$, and let's say that the actual applied stress is tensile for starters. If we load the material to the point where the stress is, for example, $500 \,\mathrm{MPa}$, then that means that the loading has surpassed the material's yield stress by $100 \,\mathrm{MPa}$ and that the material has entered the inelastic region.

If the direction of stress is now reversed, from tensile to compressive, the Bauschinger effect tells us that the new compressive yield stress will be lower than the initial one and will be $-400+100=-300 \,\mathrm{MPa}$.

What I want to know is: What happens if in my initial loading of the material I don't surpass the yield strength? In other words, if yielding occurs at $400 \,\mathrm{MPa}$, I apply less than that ($350 \,\mathrm{MPa}$, for example). If I now unload and start loading with compressive stress, does the Bauschinger effect apply? Or is the yield stress for compressive loading still $-400 \,\mathrm{MPa}$?