Análise do comportamento do par tribológico aço fundido alto C e alto Si contra o metal duro com e sem revestimento de TiN

Abstract

Cast steels with high levels of carbon (C) and silicon (Si) with bainitic structure have aroused interest in studies and applications of the metal-mechanical industry, for combining high strength and high ductility. These characteristics are due to the formation of multiple phases in its structure, which are activated after austempering heat treatment. In the manufacturing process of these materials, machining steps are implemented with the material still in the annealed state, in order to facilitate its machinability. Cast steel in the annealed state, have been studied to assess machinability and tribological behavior, which help in the more efficient selection of materials for cutting tools. Thus, this work evaluated the wear behavior of the carbide with and without a titanium nitride (TiN) coating sliding against the molten steel in the annealed state (270 ± 3 HV). The pin-on-disk (PSD) results indicated that the conjugate with the coating had the lowest friction coefficient values. However, higher values ​​of specific wear coefficient (K) were found for the conjugate with replica coating. This fact was attributed to a possible removal of the TiN coating. The work contributed to the understanding of the tribological behavior and the identification of the wear mechanisms that caused damage to the surface of the evaluated materials.