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:
May. 12, 1998
Filed:
May. 30, 1995
Masao Shiga, Hitachi, JP;
Ryo Hiraga, Hitachiota, JP;
Takeshi Onoda, Hitachi, JP;
Nobuo Shimizu, Hitachi, JP;
Norio Yamada, Hitachiota, JP;
Mitsuo Kuriyama, Ibaraki-ken, JP;
Kishio Hidaka, Hitachi, JP;
Shigeyoshi Nakamura, Katsuta, JP;
Yutaka Fukui, Hitachi, JP;
Toshio Fujita, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A steam turbine in which principal components to be exposed to high temperatures are all made of ferritic steel, whereby the temperatures of main steam and reheat steam can be increased to 610-660 (.degree.C.). The rotor shaft (23 in FIG. 1) of the steam turbine is made of ferritic forged steel whose 100,000-hour creep rupture strength is at least 15 (kg/mm.sup.2) at the service temperature of the rotor shaft. Likewise, the casing (18) is made of ferritic cast steel whose 100,000-hour creep rupture strength is at least 10 (kg/mm.sup.2). The steam turbine of high thermal efficiency can be applied to a steam-turbine power plant.