Graphitic steel compositions

摘要

A machinable, graphitic steel is disclosed having a composition in weight % of about 1.0 to 1.5 total C; 1.0 to Si; 0.3 to 1.0 Mn; up to 2.0 Ni; up to 0.5 Cr; up to 0.5 Mo; up to 0.1 S; up to 0.5 Al; balance Fe and incidental impurities. The steel is hot worked and cooled to precipitate a controlled amount of graphite for improved machinability and to achieve a controlled amount of matrix carbon for enhanced physical properties. A matrix carbon content of between about 0.2 to 0.8 weight % is desired. The steel may be further heat treated to yield further variations in the microstructure and physical properties.