Chromium and tungsten carbide coating of AISI D3 steel by a thermoreactive diffusion process

Abstract

In this study AISI D3 steel surfaces were coated with chromium and tungsten carbide by using thermoreactive diffusion process. The chromium carbide coating process was carried out at 1000degreesC and 1100degreesC for 5 hours. Chromium carbide coating process was carried out at two different compositions. One of the compositions includes powder of pure chromium, inert filler (Al2O3), carbon containing compound (C12H10), activator (NH4Cl) and the other includes powder of ferrochromium, Al2O3, C8H10 and NH4Cl. After coating process some of the chromium carbide coated specimens were quenched in water and oil. Tungsten carbide coating process was carried out at 1000degreesC for 5 hours in contact with powder of tungsten Al2O3, C12H10 and NH4Cl. At the end of thermally activated process, the carbide coatings were examined by means of optical microscopy and SEM, micro hardness measurement and X Ray diffraction. Also the adhesion of the carbide layers was examined by Rockwell-C adhesion test.