Fabrication of a high-strength steel article with inclusion control during melting

In an aircraft gas turbine (jet) engine, air is drawn into the front of the engine, compressed by an axial-flow compressor, and mixed with fuel. The mixture is combusted, and the resulting hot combustion gases are passed through an axial-flow turbine. The flow of gas turns the turbine by contacting an airfoil portion of the turbine blade, which in turn provides power to the compressor. The hot exhaust gases flow from the back of the engine, driving it and the aircraft forward. A steel article is fabricated by providing an iron-base alloy having less than about 0.5 weight percent aluminum, melting the alloy to form a melt, adding calcium to the melt, thereafter adding aluminum to the melt to increase the aluminum content of the melt to more than about 0.5 weight percent aluminum, and casting the melt to form a casting. Other calcium additions may be made simultaneously with the adding of aluminum, and after the adding of aluminum but before casting the melt. The calcium additions deoxidize the melt to minimize the formation of clustered aluminum-oxygen-based inclusions.