FURNACE OXIDATION AND CO2 CONTINUOUS LASE R-ASSISTED OXIDATION OF ELECTROLYTICAL CHROMIUM COATING ON STEEL

In order to profit from the good tribological properties of chromium o xide, a chromium deposit on low alloy steel was made using electrolysi s, then it was oxidized either using a continuous CO2 laser surface tr eatment at the constant temperature of 800 and 600-degrees-C, or in a furnace under partial oxygen pressure of 1 atm. A morphological and an alytical comparison was realized on the Cr2O3 layers obtained in the f urnace or by laser. Then, in order to understand better the diffusiona l mechanisms brought into play, during oxidation in the furnace of an electrolytical chromium deposit, a kinetic, then a diffusional study o f the oxygen in the chromium deposit was made. The Cr2O3 layers obtain ed by laser are always thicker, more homogeneous and denser than the o nes obtained in the furnace.