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:
Mar. 21, 2006
Filed:
Oct. 25, 2002
Tatsuo Fukuzumi, Tokyo, JP;
Motoki Watanabe, Utsunomiya, JP;
Tsuneo Yoshimura, Tokyo, JP;
Katsuyuki Uchibori, Chiba, JP;
Tatsuo Fukuzumi, Tokyo, JP;
Motoki Watanabe, Utsunomiya, JP;
Tsuneo Yoshimura, Tokyo, JP;
Katsuyuki Uchibori, Chiba, JP;
Mitsubishi Steel Mfg. Co., Ltd., Tokyo, JP;
Yoshimura Technical Office Inc., Tokyo, JP;
Abstract
A sulfur-containing free-cutting steel for machine structural use, containing, in weight percent, 0.10 to 0.55% of C, 0.05 to 1.00% of Si, 0.30 to 2.50% of Mn, not more than 0.15% of P, 0.050 to 0.350% of S, more than 0.010% but not more than 0.020% of Al, 0.015 to 0.200% of Nb, 0.0015 to 0.0150% of O, and not more than 0.02% of N, and further containing, in weight percent, at least one selected from the group consisting of 0.03 to 0.50% of V, 0.02 to 0.20% of Ti and 0.01 to 0.20% of Zr, wherein the ratio S/O of the S content to the O content is 15 to 120, and at least one selected from the group consisting of an oxide, a carbide, a nitride and a carbonitride of Nb(see FIG.) acts as nuclei for precipitation of MnS type inclusions. A sulfur-containing free-cutting steel for machine structural use is obtained by adjusting the chemical composition of steel and provides a sulfur free-cutting steel that does not contain lead but has a machinability and mechanical properties on a par with conventional lead-containing free-cutting steel.