The influence of aluminum on microstructure, mechanical properties and wear performance of Fe–14%Mn–1.05%C manganese steel

Abstract

In this investigation, the effect of Al addition on the microstructural evolution, mechanical properties, wear behavior/mechanism of an Fe–14%Mn–1.05%C steel was studied. For this purpose, samples with various amounts of Al contents, under the austenitized condition of 1100 °C, were first prepared. Microstructural changes were assessed using optical microscopy, field emission scanning electron microscopy (FE-SEM) that was equipped with energy dispersive spectroscopy (EDS) detector, electron backscatter diffraction (EBSD), and X-ray Diffraction (XRD). As well, mechanical properties variations were analyzed using Charpy impact test, tensile test and Vickers microhardness apparatus. A pin on disk wear test was employed for the evaluation of wear performance. To determine the wear mechanism, the wear damaged surfaces were analyzed by FE-SEM technique. Results showed that the microstructure of this steel consists of a predominant austenite phase together with a small amount of Fe1.8Mn1.2C complex carbide. Increasing the Al content of the steel increased austenite grain size and reduced the amount of carbides that were precipitated in the austenite matrix. Also, the results of wear, tensile, hardness and Charpy impact tests indicated that increasing the Al content increased the yield strength, hardness and wear resistance. However, tensile strength, ductility and energy absorption capability were significantly reduced under this circumstance. Wear test results together with the analysis of the damaged surfaces demonstrated that abrasive wear (in the form of parallel grooves) was the main wear mechanism operative in this steel. Finally, results indicated that increasing the Al content of the steel reduced friction coefficient, weight loss and the degree of surface damage.