The role of niobium for the development of wear resistant steels with superior toughness

Wear resistant steels are commonly designed to have a high hardness and at the same time good weldability due to a low alloy content. The high hardness is achieved by quenching the material to a martensitic microstructure, which requires systematic alloying with Mn, Cr, Ni and Mo. However, even for wear resistant steels, a high toughness may be advantageous, as it not only ensures good impact resistance, even at sub-zero temperatures, but can enhance the wear resistance by causing a change in the wear mechanism. Besides a high level of process-based steel cleanliness, microalloying with Nb provides the basis to enhance the toughness of the steel. The objective of this paper is to present a selected study of how microalloying with Nb in combination with a well-adapted process route can be used to obtain wear resistant steels with a superior balance of toughness and hardness. (AU) Copyright © 2018 Companhia Brasileira de Metalurgia e Mineração (CBMM) All rights reserved