Low-carbon steels are widely used in numerous industrial applications, although some limitations exist and restrict their use in more demanding environments. In the case of cast steel components, the reinforcing using metal matrix composites with ceramics during the casting process is particularly attractive, increasing the wear resistance on the outer surface or in specific areas. This method proves to be simple, without requiring specific equipment, and effective [1-3]. The combination of properties arising from the base metal (with high toughness), and the ceramic (with high hardness and wear resistance), results in a new material that is effective in competing with hard alloy steels [2].

This work presents the manufacturing procedure of reinforced low-carbon cast steel specimens and discusses the results of the microstructural analysis by SEM/EDS, XRD, EBSD and TEM. The mechanical response of the reinforced specimens was evaluated by Vickers hardness and micro-abrasion wear tests. Mixtures of Ti, Al and graphite powders were prepared and homogenised in a shaker mixer for seven hours and cold pressed at 230 MPa to obtain parallelepiped pre-forms. After that, the pre-forms were inserted into a sand mould before the steel casting. At last, the cast specimens were subject to a normalising heat treatment at 930 °C for 30 minutes.

The microstructural characterisation showed a non-uniform distribution of TiC particles, formed in situ, with a round morphology in a ferrite matrix (Figure 1). The average hardness of the composite produced (407 HV 30) is twice that of the low-carbon cast steel, and a 30% decrease in the wear rate was also achieved.