Ž . Surface and Coatings Technology 133134 2000 460465 Corrosion and tribological studies of chromium nitride coated on steel with an interlayer of electroplated chromium S. Han a , J.H. Lin b , S.H. Tsai b , S.C. Chung c , D.Y. Wang a , F.H. Lu a , H.C. Shih a,b,  a Institute of Materials Engineering, National Chung Hsing Uni  ersity, 250 Kuo Kuang Rd., Taichung 402, Taiwan ROC b Department of Materials Science and Engineering, National Tsing Hua Uni  ersity, 101 Kuang Fu Rd., Sec. 2, Hsinchu 300, Taiwan ROC c Materials Research Laboratories, Industrial Technology Research Institute, 195-5 Chung Hsing Rd., Sec. 4 Chuttung, Hsinchu 310, Taiwan ROC Abstract The electrochemical and tribological behavior of CrN coatings on steel are investigated. A single layer of chromium nitride Ž . coating is compared with a double layer of the coating CrNCrsteel in which the interlayer chromium was produced by electroplating with the aim of improving the corrosion and tribological performance of the steel. The CrN coatings are deposited by using a reactive cathodic arc plasma deposition technology in an industrial scale, while the interlayer of chromium produced by electroplating. The coating assemblies have been compared in terms of hardness, wear and corrosion resistance. The composition Ž . and structure of the chromium nitride have been studied by X-ray diffraction XRD , using both 2  diffraction mode and the glancing-incidence X-ray diffraction mode. The surface morphology was examined by using SEM. The improvement in wear and corrosion resistance after cathodic arc plasma deposition with and without a hard chrome as an interlayer are discussed in considering the microstructure changes.  2000 Elsevier Science B.V. All rights reserved. Keywords: Chromium nitride; Corrosion resistance; Tribological behavior 1. Introduction Increasing tribological and corrosion resistance of hard chrome would reduce chromium consumption in the electrodeposition industry and influence both strategic and environmental interests. Chromium is considered as a strategic metal because of its use in  metal alloys, especially steels and other alloys 1 . Hard chrome electrodeposition processes use wet chemical baths containing the hexavalent chromium ion, Cr 6 ,  Corresponding author. Tel.: 886-3-571-5131, ext. 3845; fax: 886-3-571-0290. Ž . E-mail address: hcshih@mse.nthu.edu.tw H.C. Shih . some of which is emitted into the environment as effluent or sludge. By reducing the amount of hard chrome electrodeposition, the amount of Cr 6 emitting into the environment can be proportionately reduced. If we can extend the life expectancy of electroplated Cr, namely applying CrN by physical vapor deposition Ž . PVD to improve the tribological and corrosion resis- tance of electroplated Cr, then we can have a positive impact on both strategic and environmental issues as- sociated with the use of chromium. In this work Cr  N coating assemblies were deposited by using a cathodic arc plasma deposition technique in an industrial scale   2  7 , while an interlayer of chromium produced by  electroplating 8 . Judging from tribological and corro- sion resistance, we should be careful in using the 0257-897200$ - see front matter  2000 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 2 5 7 - 8 9 7 2 00 00979-8