Desgaste por deslizamento da camada martensítica obtida por meio do SHTPN no aço inoxidável ferrítico AISI 409

Abstract

In the sequence of the research line being developed in the GrMaTS Laboratory (Grupo de Materiais, Tribologia e Superfícies), this project aims to study the effect of the martensitic layer obtained through the Solution Heat Treatment after Plasma Nitriding (SHTPN) on the tribological behavior of ferritic stainless steel AISI 409. The purpose of SHTPN is to add nitrogen in solid solution at the surface, which increases the amount of Nieq in the steel and therefore causes austenite formation during the solubilization and martensite formation after quenching. Tests were performed with the following samples: supply condition (ferritic microstructure); nitrided (with compound layer); after SHTPN (non-tempered martensite); and four martensite tempering temperatures after SHTPN. Reciprocating sliding wear tests were carried out under 5N load with coefficient of friction record, characterization of wear mechanisms through Scanning Electron Microscope (SEM) and wear track depth measurement through 3D rugosimeter. Tribological tests output data and wear mechanisms were correlated with hardness profile and top hardness. The nitrided condition presented the lowest wear depth. Sample with the highest tempering temperature revealed tribological behavior similar to the supply condition, with predominant adhesive mechanism in both cases. All the other conditions improved the wear behavior compared to supply condition, with the main wear mechanisms transiting from abrasion to adhesion.