In-situ Synthesis and Characterization of TiC-reinforced Hadfield Manganese Austenitic Steel Matrix Composite

Abstract

An in-situ TiC-reinforced Hadfield manganese austenitic steel matrix composite has been synthesized by conventional melting and casting route. The microstructure has been characterized using an optical microscope, a scanning electron microscope coupled with an energy dispersive spectrometer and X-ray diffraction. Hardness and abrasion resistance have also been measured. The microstructure of the as-cast composite consists of austenite, a-ferrite and (Fe, Mn) 3 C together with TiC particles. The microstructure of the solution-annealed (1 273 K for 36 ks) composite contains TiC particles in g matrix. It has been observed that the abrasive wear resistance of the solution-annealed composite is significantly better than that of the solution-annealed austenitic manganese steel.KEY WORDS: Hadfield manganese austenitic steel; in-situ steel matrix composite; titanium carbide; solution annealing treatment; abrasive wear resistance.then the temperature was raised to 1 883 K. The calculated amount of Fe-Ti (70 % purity) and electrolytic manganese (95 % purity) were added to the melt at this temperature. The Fe-Ti was added to iron alloy melt by plunging due to lower density of Fe-Ti with respect to iron alloy melt. The melt was stirred continuously at 1 893 K temperature for 600 s and subsequently cast in a metallic mould. The chemical compositions of the Hadfield manganese austenitic steel and TiC-reinforced composite are presented in Table 1.Metallographic samples of dimension 12 mmϫ12 mmϫ 10 mm were cut from the middle portion of the casting. The specimens were polished according to the standard metallographic technique and finally etched with 2 % nital. The samples were examined using an optical microscope (OM) and a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS). The various phases revealed by metallography were analyzed by the X-ray diffraction (XRD) analyses using the Co K a radiation.The macrohardness was measured using a Vickers hardness tester at an applied load of 30 kgf and loading time of 20 s at room temperature. The samples were first surface finished and then ten measurements were performed randomly in each sample. The average of ten measurements has been represented as the hardness of the specimen.Abrasive wear tests were carried out on 12 mmϫ 12 mmϫ10 mm samples against 220 grit SiC paper affixed to a rotating flat disc of 250 mm diameter. The rotating speed and the track diameter were fixed as 300 r.p.m. and 80 mm, respectively. The sliding velocity was fixed at 1.25 m/s. The experiments were carried out at the load of 24.5 N. As the TiC (2 900-3 200 HV) 20) particles in the composite are harder than SiC (2 850 HV) 20) abrasives, SiC particles get blunted after sliding for only 30 s. To ensure fresh supply of abrasive particles, worn SiC abrasive paper was replaced with a new one after 30 s. Wear rate of the specimens has been computed by the weight loss technique. The wear data has been plotted as cumulative volume loss (converted from weight loss) as a fu...

Influence of aging treatment on mechanical properties and wear resistance of medium manganese steel reinforced with Ti(C,N) particles

“…Prava Dalai et al [30] indicated that adding hard TiC particles into the austenitic manganese steel and secondary processing were beneficial for elastic modulus, hardness, and wear resistance. Srivastava and Das [31][32][33] demonstrated that austenite matrix with Ti(C,N) and (Ti,W)C precipitates could effectively protect the sliding surface. Huang et al [34] studied low alloy abrasion-resistant steel reinforced with self-generated TiC particles developed to improve its wear performance without increasing its hardness, and the results showed that the carbide precipitates were significantly helpful in resisting abrasive embedding and micro-cutting during abrasive wear.…”