RÉSUMÉ

An analysis of the electrodeposition process Cr²⁺+2e®Cr⁰ taking place when a voltammetry with linear scanning of the potential is applied to an initial deposit of Cr⁰, previously obtained by a standard procedure, has been carried out supposing that the kinetic limitations come especially from the site of the solution. One shows that if the electrode reaction is reversible(i.e., the diffusion is rate limiting), the applying of a voltammetry with linear scanning of the potential improves the homogeneity of the initial deposit. Further, a modelling of the electrodeposition process by two parallel reactions has been made considering that to the first reaction participate the chromium ions that have difficulties in fulfilling the tunnelling condition, while to the second reaction those that have not such difficulties. This approach has led to two criteria for analysing the kinetic behaviour of two important types of electrodes : the redox electrodes inert metal | СrС1₃ / CrCl₂, LiCl-KCl, respective the electrodes support |Cr⁰|CrCl₂, LiCl-KCl. The first criterion permits to establish if the respective electrodes behave like unielectrodes and have homogeneous surfaces. The second criterion permits to estimate the degree of homogeneity of the initial deposit of Cr⁰.