Title: Enhancement of surface properties of nanocrystalline TiN coated plasma nitrided AISI 310 austenitic stainless steel
Authors: Pankaj Kumar Singh; Arbind Kumar; Sanjay Kumar Sinha; Aman Aggarwal; Gajendra Prasad Singh
Addresses: Department of Mechanical and Automation Engineering, Amity School of Engineering and Technology, Bijwasan, New Delhi 110061, India ' Department of Mechanical Engineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India ' Department of Physics, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India ' Department of Mechanical Engineering, Ganga Institute of Technology, Haryana-124104, India ' Centre for Nanotechnology, Central University of Jharkhand, Brambe, Ranchi, Jharkhand 835205, India
Abstract: The surface modification with combination of plasma nitriding and TiN coating on 310 stainless steel significantly improved the surface hardness and corrosion properties. X-ray diffraction showed the expanded austenite, CrN and TiN phases along with austenite phase. The nitrided layer was found in 10-50 μm range and the TiN layer was about 200 nm. The Raman band at 803 cm−1 corresponds to an untreated sample. The bands at 220 cm−1, 250 cm−1, and 468 cm−1 is for CrN/Cr2N and at 280 cm−1 and 589 cm−1 for TiN. The hardness is increased from 1.6 GPa to 10.4 GPa after coating. The corrosion current density about 4.6 × 10−7 Acm−2 was measured and the ICR was reduced from 90 mΩcm2 to 11 mΩcm2 at 150 N cm−2 after coating. The enhancement in conductivity after coating is due to conductive nature of TiN particles which might be providing a path for electron transportation.
Keywords: austenitic steel; plasma nitriding; TiN; corrosion; hardness; interfacial contact resistance; ICR.
International Journal of Surface Science and Engineering, 2017 Vol.11 No.6, pp.547 - 562
Received: 01 Dec 2016
Accepted: 22 Apr 2017
Published online: 29 Dec 2017 *