Passive Properties of Magnetron-Sputtered CrN Film on AISI 304 Stainless Steel.

Authors :: Shujun Gao
Chaofang Dong
Xuequn Cheng
Kui Xiao
Lei Wang
Xiaogang Li
Source :: Corrosion; Jun2014, Vol. 70 Issue 6, p627-635, 9p
Publication Year :: 2014
Abstract: The passive properties of chromium nitride (CrN) film deposited on AISI 304 stainless steel (UNS S30400) by magnetron sputtering were investigated using a series of electrochemical techniques. The results showed that the passive film followed the 3D grain growth. The nucleation type was instantaneous while it deviated to progressive gradually with the increase of sodium chloride (NaCl) content. The thickness of the passive film was 1.1 nm to 2.4 nm with the compositions mainly of Cr, CrN, chromic oxide (Cr<subscript>2</subscript>O<subscript>3</subscript>), chromic hydroxide (Cr[OH]<subscript>3</subscript>), and chromium trioxide (CrO<subscript>3</subscript>). With the increase of film formation potential, the vacancy density decreased exponentially. The obtained diffusion coefficient of defects was 5.493x10<superscript>-17</superscript> cm²/s. Chromium cation in the CrN cation site also participated in the growth of passive film. Anions (Cl<superscript>-</superscript>) could adsorb on the passive surface in the free corrosion potential condition. [ABSTRACT FROM AUTHOR]