Ciclagem térmica no aço AISI 1020 com revestimento de carboneto de tungstênio via HVO

Abstract

Nowadays in the metal-mechanic industry there is a growing expansion in technological research of the materials, aiming to increase specific properties for industrial applications. In the area of manufacture by the process of mechanical conformation a great barrier is the border between plasticity and elasticity; which presents, by process characteristic, wear on tools and matrices. Therefore, the application of the metallic coating Tungsten Carbide on its surfaces presented itself as a good reducer of this damage. Even in many processes the need arises to implement heat, as in hot forming, to reduce wear and facilitate deformation of the material, however this coating did not show good resistance in these hot processes, so the study of this work is to evaluate the impact when requested by thermal cycling. With this methodology, the microhardness and thermal shock tests were adopted, as well as the optical and electronic microscope analyzes. The samples analyzed are with the coating sprayed via HVOF, polished finish and rectified by CO2 laser. The results presented were the exposure of the brittleness of the material when requested by thermal stress, even reducing the hardness. With the analysis of the coefficients of expansion, it was shown that this coating when sprayed on steel, whatever its composition, does not present resistance to thermal cycling.