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. 24, 1992
Filed:
Jun. 19, 1990
Tsunahiro Yamakawa, Fuji, JP;
Satoru Nito, Fuji, JP;
Hiroyoshi Yamakawa, Fuji, JP;
Ichiro Kokubo, Kakogawa, JP;
Takuo Hosoda, Akashi, JP;
Masakatsu Hata, Kusakabe, JP;
Yamakawa Industrial Co., Ltd., Fuji, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
Steel containing, on a weight percent basis, 0.01 to 0.15% of carbon, 0.05 to 0.50% of silicon, 0.20 to 1.0% of manganese, 0.01 to 0.1% of aluminum, 0.3 to 2.0% of copper, 0.1 to 2.0% of nickel, 0.015 to 0.1% of niobium and 0.0005 to 0.0050% of calcium, the balance of its composition being iron and unavoidable impurities, is heated to a temperature of 1100.degree. C. to 1250.degree. C., and hot rolled. The hot-rolled steel is coiled at a temperature of 350.degree. C. to 500.degree. C. to prepare a hot-rolled steel sheet having a tensile strength not exceeding 65 kgf/mm.sup.2. The sheet is cold worked until a working strain of at least 15% is set up. The cold-worked product is heated at a temperature of 400.degree. C. to 550.degree. C. for 0.5 to three hours to yield a part having a tensile strength of at least 80 kgf/mm.sup.2 for an automobile, particularly its automatic transmission system.