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:
Oct. 28, 2008
Filed:
Oct. 18, 2004
Makoto Takahashi, Hirakata, JP;
Kunihide Hashimoto, Katano, JP;
Makoto Takahashi, Hirakata, JP;
Kunihide Hashimoto, Katano, JP;
Kubota Corporation, Osaka-Shi, JP;
Abstract
A heat-resistant cast steel excellent in high-temperature strength, aged ductility and creep rupture strength for use as a material for steam reforming reaction tubes in fuel cell hydrogen generation systems and the like. The cast steel has a chemical composition comprising, in mass %, 0.1 to 0.5% of C, up to 2.5% of Si, up to 2.5% of Mn, 15 to 26% of Cr, 8 to 23% of Ni, 0.1 to 1.2% of Nb, 0.01 to 1.0% of Ti, 0.001 to 0.15% of Ce, up to 0.06% of N and the balance substantially Fe, the cast steel being 20 to 45 in the parameter value P calculated from the expression:When desired, the steel contains at least one of 0.001 to 0.05% of B, 0.01 to 0.5% of Zr and 0.001 to 0.15% of La, and/or 0.01 to 0.3% of Al. Further when desired, the C, Cr and Ni contents are limited to 0.1 to 0.3% of C, 15 to 20% of Cr and 8 to 18% of Ni.