Die chemischen Gleichgewichte bei der Inchromierung von Stahl

The chemical equilibria encountered with the chromium-plating of steel In order to determine the equilibrium conditions, the authors investigated, in the compound system Fe(s) + CrJ₂(g) ? Cr(s) + FeJ₂(g) used for diffusion-type chromium plating, the two stages Cr(s)+ 2J(g) ? CrJ₂(g) and Fe(s) + 2J(g) ? FeJ₂(g) which determine the reaction rate. The former stage was investigated at a temperature range of 700 to 1160° C, the latter at 760 to 1080° C. In this temperature range, the equilibrium is shifted somewhat to the left, the shift increasing with higher temperatures. However, as the general correlation of the equilibrium constants with temperature is low, it may be assumed that chromium-plating could be carried out over a much wider temperature range than is usual at present.