The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 2004
Filed:
Jun. 07, 2002
Takashi Kano, Nagoya, JP;
Yutaka Kurebayashi, Nagoya, JP;
Daido Steel Co., Ltd., Nagoya, JP;
Abstract
Disclosed is a free-cutting steel for machine structural use which always exhibits desired machinability, particularly, machinability by cutting with cemented carbide tools. This free-cutting steel is produced by preparing a molten alloy of the composition consisting essentially of, by weight %, C: 0.05-0.8%, Si: 0.01-2.5%, Mn: 0.1-3.5% and O: 0.0005-0.01%, the balance being Fe and inevitable, and adjusting the addition amounts of Al and Ca in such a manner as to satisfy the above ranges, S: 0.01-0.2%, Al: 0.001-0.020% and Ca: 0.0005-0.02%, and the conditions of [S]/[O]: 8-40 [Ca]×[S]: 1×10 −1×10 [Ca]/[S]: 0.01-20 and [Al]: 0.001-0.020% to obtain a steel characterized in that the area in microscopic field occupied by the sulfide inclusions containing Ca of 1.0% or more neighboring to oxide inclusions containing CaO of 8-62% is 2.0×10 mm or more per 3.5 mm .