The challenge of accurate prediction of industrial wear performance from laboratory tests

Several plant wear trials and several laboratory test methodologies are described and analysed. Each example is evaluated in terms of its success (or lack thereof) in yielding useful quantitative performance data for candidate wear-resistant materials. Field trials are challenging, though if performed with sufficient care and resources they can yield useful quantitative data. To be useful, a laboratory test must satisfy several performance criteria, notably: It should simulate with reasonable fidelity both the macro-mechanics and micro-mechanics of the conditions present in the field; it should be validated against field trials and confirmed to produce accurate quantitative performance predictions for various classes of materials; it should not be excessively sensitive to precise set-up conditions; and it should provide reasonable data productivity and statistical quality. Rather than attempting to break down a complex industrial wear process into its individual component mechanisms and “engineer” each of th se mechanisms in the laboratory, fidelity is more likely to be achieved by a mechanically simple device that preserves the natural complexity of the industrial wear process. In the process of the case studies, commentary is given on two key modes of abrasive wear, namely high normal stress abrasion (HNSA) and low stress sliding abrasion (LSSA). An important lesson from this analysis is the fundamental observation that LSSA does not equate to low wear rates; indeed, the highest wear rates observed industrially are from LSSA, due to the dominance of tangential sliding and high tonnage throughputs. The nature of LSSA is such that materials selection has the capacity to achieve much greater percentage improvements in component service life than is possible in HNSA situations. The proposed new generation of field-validated laboratory tests will provide confidence to invest in the development of superior wear-resistant materials. One promising class of wear-resistant casting alloy is a “double composite” in which niobium-rich carbides provide additional reinforcement to a conventional chromium carbide eutectic cast iron. (AU) Copyright © 2018 Companhia Brasileira de Metalurgia e Miner ção (CBMM) All rights reserved