Search:

I am afraid you need to remove pins to check it out. If you did not tighten pins up and unfolding the razor seems to be harder, rust can be the case.
You can also use some rust remover liquid, but...

Applying mineral oil to a carbon steel blade is always a good practice and it should be done every time you finish shaving, clean the blade and store the razor.
If you are noticing your razor does...