Estudo dos efeitos do processo de refusão por laser de fibra em um aço SAE 1020 revestido com Carbeto de Tungstênio via HVOF

Abstract

Wear is a phenomenon that occurs due to the contact between surfaces, resulting in modifications and possible problems over time. These problems are often found in agricultural machine components due to the contact between grains and metal surfaces. In view of the need to reduce the problems caused by abrasive wear in equipments that have direct contact with moving grains, the study aims to evaluate the effects of the Yb (Ytterbium) fiber laser remelting process on a SAE 1020 steel with WC (Tungsten Carbide) surface coating deposited via thermal spray by the HVOF (High Velocity Oxygen Fuel) method. This coating has high hardness, which is the main factor that contributes to abrasive wear resistance. The fiber laser remelting process increases the adhesion of the coating to the substrate. Thus, five different laser parameters were applied in order to obtain the best adhesion between the layers and the best abrasion resistance. Through metallographic analysis with SEM (Scanning Electron Microscopy) and microhardness tests it was possible to determine the best laser application parameter. This parameter was then evaluated in the abrasive wear test according to ASTM G65. Thus, for the best parameter, Thus, for the best parameter, the results obtained were the following: a coating thickness of 301.8 μm, the highest average microhardness value of 1308.43 HV and an average volume loss rate of 0.2472 mm3/min. When compared to the bibliographic values, the results were considered satisfactory, since it was evident the improvement in the adhesion of the WC coating on SAE 1020 steel and the good resistance to abrasion wear.