Effect of frequency on the properties of plasma nitrided AISI 4340 steel Alphonsa J.1, Sinha G.1,2, Kumar A.1,2, Jhala G.1, Tiwari S. K.1,3, Gupta S.1, Rayjada P. A.1, Chauhan N.1, Raole P. M.1, Mukherjee S.1 1Facilitation Centre for Industrial Plasma Technologies, Institute for Plasma Research, Gandhinagar, Gujarat. 2Metallurgical and Material Engineering Division, Indian Institute of Technology, Kharagpur. 3Applied Chemistry and Corrosion Division, National Metallurgical Laboratory, Jamshedpur-831007. Abstract The paper presents the results of investigations of the structure and corrosion resistance of AISI 4340 steel after plasma nitriding with 10 kHz and 30 kHz pulse frequencies. Properties of the nitrided layer were analysed by using Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD) and micro-Vickers hardness tester. Corrosion rates were monitored through polarisation resistance technique using 3% NaCl solution. In our present work, it was found that plasma nitriding with 30 kHz frequency gave better corrosion resistance and higher surface hardness than 10 kHz on AISI 4340 steel. Top Keywords Plasma nitriding, Pulse frequency, AISI 4340 steel. Top |