Study of carbon concentration on the nanostructural and corrosion properties of Zr(C, N)/ss304 films

¹ Agricultural, Medical and Industrial Research School, Nuclear Science & Technology Research Institute (NSTRI), P.O. Box 31585, -498, Karaj, Iran
² Department of Physics, Karaj branch, Islamic Azad University, Karaj, Iran
³ Corrosion Lab., Materials Eng. Dep., Islamic Azad University, Tehran, Iran
⁴ Plasma physics Research Centre, Islamic Azad University, P.O. Box 14665, -678, Tehran, Iran

Corresponding author: mmojtahedzadeh@nrcam.org

Received: 7 July 2008
Accepted: 27 January 2010
Published online: 26 March 2010

Abstract

The improvement of corrosion resistance of ZrN_1-xC_x films (0 ≤ x ≤ 1) on AISI stainless steel (ss) 304 is studied as a function of methane flow rate introduced into mixture of argon and nitrogen gases (Ar + N₂). The films were deposited using ion beam sputtering technique at 400 °C and their corrosion resistance has been investigated via electrochemical test using 0.5 M H₂SO₄ solution. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to study the micro and nano-structures of the films. Film stoichiometry was determined by Rutherford backscattering (RBS) technique using SIMNRA code. An average grain size of 7 nm was calculated for deposited films using Scherrer's formula. X-ray diffraction results showed the presence of a transition crystalline phase from ZrN to ZrC phase corresponding to the formation of ZrN_1-xC_x crystalline phase. The electrochemical test revealed that the film corrosion resistance increased with increasing x values. Furthermore, micrographs obtained by SEM did not indicate any damage on the sample surface due to corrosive agent attacks for x > 0.6.