Rabah BOUBAAYA, Younes BENARIOUA, Omar ALLAOUI

Effect of the annealing temperature and the thickness of carburizing layer on the obtained chromium carbides

Low carbon steel substrates were surface hardened by carburizing in solid medium, and then thin layers of chromium were deposited by electrolytic way. After chromium deposition, the samples were exposed to isothermal annealing at temperatures between 500 and 1100 °C for 1 and 2 hours duration. The obtained thin layers were characterized by X-rays diffraction, optical microscopy and Vickers micro-hardness. The obtained results showed that chromium layers are transformed into chromium carbide by metastable phases of transition. At 500 °C annealing temperature thin films retain their monophasic character Crα, and they almost keep the same hardness values. When temperature range is between 700 and 900 °C the incipient phase appears and is increased while the chromium mother phases decrease. After annealing at 1100 °C, the chromium layer is completely converted into chromium carbides that would be responsible for the increase of the hardness and adhesion layer / substrate.

Keywords:

Diffusion Precipitation,

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[1] I. Yan-mei Jiang, Cathodic spray aided by computer, thesis of Orsay university, 1992.
[2] A. Hermann. Jehn, Multicomponent and multiphase hard coatings for tribological applications. Surface and Coatings Technology 131(2000) 433-440.
[3] M. Brizula et al, Magnetron Sputtering of CrAlN Coatings: Mechanical and tribological study, Surface and Coatings Technology 200 (2005) 192-197.
[4] M. Oden, J. ALmer, G. Hakansson, M. Olsson, Microstructure–property relationships in arc-evaporated Cr–N coatings. Thin Solid Films 377-378 (2000) 407-412.
[5] D. Dijkkamp, T. Venkatesan, X. D. Wu, S. A. Shaheen, N. Jisrawi, Y. H. Min-Lee, W. L. McLean and M. Croft, Preparation of Y-Ba-Cu oxide superconductor thin films using pulsed laser evaporation from high T c bulk material. Appl. Phys. Lett. 51, 619 (1987).
[6] C.Y. Wei, F.S. Chen, Thermoreactive deposition /diffusion coating of chromium carbide by contact-free method, Materials Chemistry and Physics 91 (2005) 192-199.
[7] A. Prôner,Thermal spray coatings, Engineering Techniques, Vol. (MD3), M1645, pp11-12.
[8] Y. Benarioua, Study of a new titanuration technique of tool steels , thesis of polytechnic school (El Harrach), 1993.
[9] C. P. Constable, D. B. Lewis, J. Yarwood, W. –D. Munz, Raman microscopic studies of residual and applied stress in PVD hard ceramic coatings and correlation with X-ray diffraction (XRD) measurements. Surface and Coatings Technology 184 (2004) 291–297.
[10] S. Sen, Influence of chromium carbide coating on tribological performance of steel. Materials & Design 27(2006) 85–91.