Cutter rings with non-uniform niobium carbide distribution for tunnel boring

Cutter rings made by centrifugal casting out of niobium alloyed steel were developed to be used in tunnel boring machines. The new material has great potential to replace conventional forged tool steel rings for cutting hard rock. Due to applying high centrifugal acceleration forces during the casting process, primary precipitated carbides with MC-structure are concentrated in the most wear affected zone of the cutter ring, thus leading to higher wear resistance of such rings. The carbide distribution across the cutter ring profile can be adjusted by production process parameters and the chemical composition of the melt. (AU) Copyright © 2018 Companhia Brasileira de Metalurgia e Mineração (CBMM)All rights reserved