Title:
FERRITIC HEAT-RESISTANT STEEL
Document Type and Number:
WIPO Patent Application WO/2007/091535
Kind Code:
A1
Abstract:
Disclosed is a ferritic heat-resistant steel which has the following chemical
composition (by weight): C: 0.01-0.10%; Si: 0.30-1.0%; P: 0.02 or less; S: 0.010%
or less; Mn: 0.2-1.2%; Ni: 0.3% or less; Cr: 8.0-11.0%; Mo: 0.1-1.2%; W: 1.0-2.5%;
V: 0.10-0.30%; Nb: 0.02-0.12%; Co: 0.01-4.0%; N: 0.01-0.08%; B: not less than
0.001% and less than 0.010%; Cu: 0.3% or less; and Al: 0.010% or less, provided
that the chemical composition satisfies the following equations: Mo(%) + 0.5xW(%)
= 1.0-1.6, and C(%) + N(%) = 0.02-0.15%, and which comprises a tempered martensite
single-phase tissue produced by thermal refining. The steel shows an excellent
long-term creep rupture strength even when used at a steam temperature around
650˚C and also has excellent water vapor oxidizability. When the value
represented by the equation: Al(%) + 0.1xNi(%) is adjusted to 0.02 or less, the
creep strength can be more stabilized.
Inventors:
FUJITA TOSHIO (JP)
SATO TAKASHI (JP)
TAMURA KOHJI (JP)
SATO TAKASHI (JP)
TAMURA KOHJI (JP)
Application Number:
PCT/JP2007/051968
Publication Date:
August 16, 2007
Filing Date:
February 06, 2007
Export Citation:
Assignee:
BABCOCK HITACHI KK (JP)
FUJITA TOSHIO (JP)
SATO TAKASHI (JP)
TAMURA KOHJI (JP)
FUJITA TOSHIO (JP)
SATO TAKASHI (JP)
TAMURA KOHJI (JP)
International Classes:
C22C38/00; C22C38/54
Foreign References:
| JP2002180208A | 2002-06-26 | |||
| JP2002235154A | 2002-08-23 | |||
| JP2002241903A | 2002-08-28 | |||
| JP2528767B2 | 1996-08-28 | |||
| JP2005023378A | 2005-01-27 |
Other References:
R. VISWANATHAN ET AL., MATERIALS FOR ULTRASUPERCRITICAL COAL-FIRED POWER PLANT BOILERS, pages 146 - 157
R. BLUM ET AL.: "Materials Development in Thermie Project for 700°C USC Plant", COMMITTEE OF THE 8TH ULTRA-STEEL WORKSHOP, STEEL RESEARCH CENTER, NATIONAL INSTITUTE FOR MATERIALS SCIENCE, 22 July 2004 (2004-07-22), pages 158 - 176
HARUYAMA ET AL.: "Influence of Pd addition on the steam oxidation behavior of 9Cr ferrite steel", MATERIAL AND PROCESS, THE IRON AND STEEL INSTITUTE OF JAPAN, vol. 16, no. 3, March 2003 (2003-03-01), pages 648
GABREL J ET AL.: "Status of development of the VM12 steel for tubular applications in advanced power plants", PROCEEDINGS OF THE 8TH LIEGE CONFERENCE PART II, MATERIALS FOR ADVANCED POWER ENGINEERING 2006, FORSCHUNGSZENTRUM JULICH GMBH, September 2006 (2006-09-01), pages 1065 - 1075
See also references of EP 1988182A4
R. BLUM ET AL.: "Materials Development in Thermie Project for 700°C USC Plant", COMMITTEE OF THE 8TH ULTRA-STEEL WORKSHOP, STEEL RESEARCH CENTER, NATIONAL INSTITUTE FOR MATERIALS SCIENCE, 22 July 2004 (2004-07-22), pages 158 - 176
HARUYAMA ET AL.: "Influence of Pd addition on the steam oxidation behavior of 9Cr ferrite steel", MATERIAL AND PROCESS, THE IRON AND STEEL INSTITUTE OF JAPAN, vol. 16, no. 3, March 2003 (2003-03-01), pages 648
GABREL J ET AL.: "Status of development of the VM12 steel for tubular applications in advanced power plants", PROCEEDINGS OF THE 8TH LIEGE CONFERENCE PART II, MATERIALS FOR ADVANCED POWER ENGINEERING 2006, FORSCHUNGSZENTRUM JULICH GMBH, September 2006 (2006-09-01), pages 1065 - 1075
See also references of EP 1988182A4
Attorney, Agent or Firm:
MATSUNAGA, Takayoshi et al. (15-2 Nihonbashi 3-chom, Chuo-ku Tokyo 27, JP)
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