Quench polish quench

[3] The process starts with a standard salt bath nitrocarburizing cycle, which produces a layer of ε iron nitride.

Finally, the workpiece is re-immersed into the salt quench bath for 20 to 30 minutes, rinsed, and oil dipped.

This last step optimizes the corrosion resistance by creating a layer of iron oxide about 3 to 4 micrometers thick.

[3][6] The chart on the right shows a comparison of corrosion resistance against other surface treatments, based on field immersion tests.

[citation needed] The chart on the right shows a comparison of the corrosion resistance of surface treated steel automotive steering columns based on the ASTM B117 salt spray test.