Análisis microestructural de revestimientos de fundiciones blancas hipoeutécticas con adiciones de Si y V

Abstract

Microstructural analysis of hypoeutectic white cast iron coatings with Si and V additions. Alloy systems used as coatings in surfaces under low or moderate abrasion are highly complex. In order to search for a simpler system, in this work three coatings were studied, applied using electrodes with different compositions, based on hypoeutectic white cast irons, with 3.2% C, V from 0.47 to 1.57%, and Si from 2.30 to 3.82%. Resulting coatings were studied using Optical (OM) and Scanning Electron Microscopies (SEM), X-ray diffraction (XRD) and hardness measurements. Results showed that maximum hardness (64 HRC) was obtained for low Si and V contents, due to a microstructure mainly composed by martensite and austenite. The increase in Si and V contents led to significant modifications in the microstructures, being perlite the main phase, with the presence of eutectic zones and V carbides. These modifications originated lower hardness for these coatings (57 HRC). This study allowed to define that using low Si and V contents (close to 2.30% Si and 0.47% V), electrodes of the Fe-Si-V-C system can be an alternative for coating surfaces under low or moderate abrasive wear.