Corrosion Behaviors and Mechanical Properties of CrN film

Corrosion behaviors and mechanical properties of CrN film were evaluated. The CrN film was deposited on the surface of H13 steel by the magnetron sputtering method. The corrosion behaviors of the uncoated and CrN coated samples were studied in air-saturated 3.5 wt.% NaCl solution with various solution pHs, i.e., pH 2, 7 and 10 at 27 degrees C by the electrochemical technique. The mechanical properties of the CrN coated samples were evaluated using nanohardness, ball on disk and scratch testers. The results revealed that the CrN coated samples had higher corrosion resistance than the uncoated samples at all pHs. Smooth substrate roughness enhanced corrosion resistance and also decreased the wear rate of the CrN coated samples on H13 steel. Corroded area was evaluated by synchrotron X-ray photoemission electron spectroscopy. It revealed that corrosion resistance of the CrN film was from oxidation of Cr into Cr2O3.