Free-cutting steel
AssigneeDaido Steel Co., Ltd.
InventorsMasakazu Hayaishi, Yutaka Kurebayashi
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Abstract
Disclosed is a free-cutting steel which exhibits good machinability in turning and small roughness of the turned surfaces, and in which substantially no macro-streak-flaw occurs. The free-cutting steel contains, by weight %, C: 0.03-0.20%, Mn: 0.5-3.0%, P: 0.02-0.40%, S: more than 0.2% up to 1.0%, one or both of Ti and Zr (in case of both, the total amount): 0.01-3.0%, O: 0.0005-0.0050% and Pb: less than 0.01%, the balance being Fe and inevitable impurities. The steel is characterized in that it contains, as the inclusion therein, Ti-based and/or Zr-based carbosulfide compound or compounds. The steel may further contain at least one from the group of Bi: up to 0.4%, Se: up to 0.5% and Te: up to 0.1%.
Claims3
A free-cutting steel which consists essentially of, by weight %, C:
- 0.03-0.20%, Mn:
- 0.5-3.0%, P:
- 0.02-0.40%, S:
- more than 0.2% up to 1.0%, one or both of Ti and Zr (in case of both, the total amount):
- 0.01-3.0%, O:
- 0.0005-0.0050% and Pb:
- less than 0.01%, the balance of Fe and inevitable impurities, the steel containing, Ti-based and/or Zr-based carbosulfide compound or compounds as inclusions therein.
Dependencies are inferred from the claim text.