Abrasion resistant metallic alloys for the mining industry

In the mining industry, abrasion is the most significant wear mechanism. The resistance to abrasion is a property that must be combined with other material properties, such as toughness and corrosion resistance. In the crushing, grinding and material handling operations, the most relevant wear resistant materials are steels and cast iron. Pearlitic and martensitic steels compete in applications, such as lifters and liners for SAG mills. Martensitic steel can also be the material choice for large balls for SAG mills, chutes and wear plates for heavy trucks. Austenitic manganese steel remains the proper choice for jaws or cone crushers. In applications with lower impact demands, high chromium cast irons are widely used for balls and liners. All these materials are subjected to increasingly higher stresses as the size of all such equipment is increasing over time. The wear performance of such steels has been improved by refining the pearlite, increasing the hardness of martensite and increasing the work hardeni g of austenite. In cast iron, the approach has been to optimize the matrix hardness and adjust the carbide content according to the application. Niobium has been investigated in the improvement of wear resistance due to its multiple effects; Niobium can harden pearlite due to grain refinement, it can harden the martensite due to precipitation hardening and can form very hard NbC carbides from the melt. This paper critically reviews the literature with regard to improvement of the abrasive wear resistance of pearlitic, martensitic and austenitic steels, and high chromium cast irons. This paper also presents test results obtained from different materials containing niobium, with the aim of ranking them for applications where abrasion is the predominant wear mechanism. (AU) Copyright © 2018 Companhia Brasileira de Metalurgia e Mineração (CBMM) All rights reserved