Alternative Air Induction Melt–Remelt Processing of an Fe3Al–C Intermetallic Alloy: Part I—Mechanical Properties and the Effects of Loading Rate, Heat Treatment and Test Temperatures

Iron aluminides based on Fe3Al intermetallic structure are known by their good corrosion and oxidation resistance. However, the hydrogen embrittlement is an issue generated by passive Al2O3 formation due to Al reaction with atmospheric water vapor. Thus, the main aim of this study was to evaluate the effects of loading rate, heat treatment and temperature of test on the mechanical properties of a Fe–Al–C alloy. Mechanical properties analysis and the incidence of hydrogen embrittlement were performed in a Fe3Al–C alloy (Fe–15.2Al–1.1C wt%), which was melted and remelted in an induction furnace. Tensile and Charpy impact tests were carried out at room temperature (as-cast and heat-treated conditions) and temperatures up to 600 °C, in order to evaluate the influence of different temperatures, heat treatment, and load rates (tensile and impact) on hydrogen embrittlement. Furthermore, the fractography was performed by SEM, helping to understand the fracture mechanisms. The heat treatment generated specimens with higher tensile resistance, however, with no effect on impact resistance, demonstrating that hydrogen embrittlement generates more damage in lower load rate tests. The tests at higher temperatures demonstrated improvement in the impact and tensile properties and regarding all conditions the fracture after tensile tests presented more brittle aspects than after impact tests.