cutting any material using any method WILL work harden the cut to some extent. it just depends on the method used to cut whatever material and the tool used to do said cut.
dull cutting tools will work harden the material more than sharp cutting tools.
it's just the nature of the process. some materials will show this way more than others on secondary operations.
aluminum, stainless, brass, mild steel, or other material, if one works with enough materials over time, you will eventually come to see this in real time.
just my observations as a machinist for a 45 year career before retirement, and still practicing today.
your mileage will vary.