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:
Jul. 14, 1998
Filed:
Jul. 15, 1996
Sang-ho Kim, Seoul, KR;
Kia Motors Corporation, Seoul, KR;
Abstract
A method of making an exhaust valve for use in an automobile is disclosed. The exhaust valve is manufactured by forging Ti-6Al-2Sn-4Zr-2Mo-0.1Si alloy at a temperature of 1000.degree.-1200.degree. C., and annealing the forged alloy by cooling after maintaining it at a temperature of 1020.degree.-1060.degree. C. for 0.5-1.5 hours. The method further includes the step of stress relieving the forged alloy, the stress relieving step including a cooling step after maintaining the forged alloy at a temperature of 600-700.degree. C. for 1.5-2.5 hours. A strain rate of the forging step is 0.5-5/S, and the cooling of the annealing step includes a control cooling step at 0.6.degree.-0.7.degree. C./sec or the cooling of the stress relieving step includes an air cooling step. The exhaust valve has improved hardness.