Study on the High Temperature Resistance of An Arc-Sprayed Chrome-Nickel Coating

The high temperature resistance behavior of an electric arc-sprayed Cr20Ni80 coating was studied in the range between 500 and 1100^oC. The phase analysis in combination with SEM analysis made at the cross-sections of the coating allowed investigating the effect of the heating time and the temperature on the formation of the oxidation products. By determination of the weight change with time of the coated specimens at different temperatures, some thermo-dynamical parameters were calculated including the activation energy of the process. The obtained results show a significant effect of surface polishing preparation in slowing down the rate of the high temperature oxidation process of the CrNi coating in comparison with the roughened (as pulverized) specimens. The thermo-dynamical analysis was also effectuated on the specimens made from low carbon steel for comparison.