Surface modification of AISI-420 steel by cathodic cage plasma niobium nitride deposition

Abstract

AISI-420 martensitic steel is used in several applications due to its high corrosion resistance. A niobium nitride coating is deposited on steel by cathodic cage plasma deposition (CCPD) to upgrade the surface properties. The X-ray diffraction shows that the coating has a tetragonal Nb4N5 structure in each condition. The nano-hardness of the untreated sample (2.5 GPa) is increased up to 15.5 and 18.7 GPa at 400°C and 450°C, respectively. A ball-on-disc wear tester is applied for wear analysis, and the wear rate is found to be reduced up to six times by coating. This study shows that the CCPD can be used successfully for depositing niobium nitride coating with outstanding mechanical and tribological properties of AISI-420 steel.