LIGAS AÇO MATRIZ + NbC - CARACTERIZAÇÃO

Abstract

This work is part of a research line in which the “matrix steel concept + NbC” is used to develop alloys with the AISI M2 high speed steel matrix (Fe bal. - 0.5 wt%C – 2 wt%W – 3 wt%Mo – 4.6 wt%Cr – 1 wt%V) and different volume fractions of niobium carbides. Five alloys were cast to obtain one with the matrix of the AISI M2 HSS composition and the others with Niobium (2.5% and 5%) and stoichiometric carbon to produce NbC carbides. Titanium was added in 0.1wt% to modify de NbC carbides morphology. The alloys were characterized by optical microscopy and scanning electron microscopy. The alloys microstructures are correlated to phase equilibrium diagrams and Scheil solidification diagrams, calculated with the CALPHAD methodology, allowing to define the alloys solidification path. It is verified a good correlation between the equilibrium and Scheil solidification diagrams and the as cast microstructure