SYMPOSIA PAPER Published: 01 January 1981

Additives to Steel and Iron for Improved Machinability


The properties required from free machining steels are machinability and surface finish; detrimental effects are the products of deoxidation. This paper describes the difficulties involved in producing high-carbon or continuously cast free machining steels, and the reasons for the virtual absence of free machining irons. Sulfur and lead as machinability promoters of steels, and the importance of the manganese/sulfur ratio, are considered, along with the forms available, manner of usage, recoveries, and recoveries from remelting scrap. The following topics are also discussed: ASTM specifications; phosphorus and nitrogen as chiefly surface finish promoters; manner of manufacture of ferrophosphorus and its properties and trends as affecting the steelmaker; products available, manner of usage, and recoveries from remelting scrap; nitrided alloys and their ASTM standards, manner of usage, recoveries, and recoveries from remelting scrap; selenium and tellurium as machinability enhancers; and possible future trends in the development of alloys for free machining steels.

Author Information

Peters, AT
Inland Steel Co., East Chicago, Ind.
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: A09
Pages: 191–198
DOI: 10.1520/STP27693S
ISBN-EB: 978-0-8031-4805-5
ISBN-13: 978-0-8031-0744-1