My component is worn

A worn shaft, roll or rotor usually has a sound core and a spent surface. Hard chrome plating or thermal spray puts material back; grinding brings it to the drawing. The part goes back into service, often with a harder surface than it started with.

Which process depends on the part and how much material is gone — hard chrome runs from .0001" for corrosion protection up to .050" for rebuild, and weld build-up covers the heavier end.