Production of an austenitic steel matrix composite reinforced by in-situ nodular eutectic: the role of Si

Excerpt

Particle-reinforced metal matrix composites have higher strength and wear resistance than that of its matrix material because the particle phases impart resistance to abrasive wear [1‐4]. However, these materials are generally not widely used due to the complex manufacturing processes required coupled with high costs. Austenitic steel has been widely used as a wear-resistant material because austenite exhibits excellent strain hardening under high energy impact wear [5]. Yet, it has poor wear resistance under low-to-medium energy impact wear. White cast iron has high wear resistance because the eutectic carbide can strongly resist abrasive wear but it suffers from low strength and poor toughness. To overcome these deficiencies, a new type of austenitic steel matrix wear-resistant composite reinforced by in situ nodular eutectics, was created [6]. These composites possess the advantages of an austenite matrix coupled with the wear resistant of white cast iron. This composite shows high strength, high toughness, and high wear resistance [6]. Till this time, thermodynamics of forming the eutectic and the effect of Si on the solidification behavior of this composite has not been studied in detail. The aim of this research was to develop a new method for producing this steel matrix composite reinforced with an in situ nodular eutectic by controlling the solidification structure of the steel. Furthermore, the effect of Si on thermodynamics of formation of the eutectic in this composite has been examined. This provides a new method for controlling the solidification products from the steel melt. …