Title:
FERRITIC HEAT−RESISTANT STEEL AND METHOD FOR PRODUCTION THEREOF
Document Type and Number:
WIPO Patent Application WO2002086176
Kind Code:
A8
Abstract:
A ferritic heat−resistant steel which comprises, in wt %, 1.0 to 13 % of chromium, 0.1 to 8.0 % of cobalt, 0.01 to 0.20 % of nitrogen, 3.0 % or less of nickel, 0.01 to 0.50 % of one or more elements selected from the group consisting of vanadium, niobium, tantalum, titanium, hafnium and zirconium, which form MX type precipitates, and 0.01 % or less of carbon, as constituting elements, the balance being substantially composed of iron and inevitable impurities, and has a metal structure wherein MX type precipitates are formed over the whole of grain boundaries and the surface within grains and M23 C6 type precipitates are present on grain boundaries in an area percentage of 50 % or less. The ferritic heat−resistant steel exhibits excellent creep characteristics even at a high temperature exceeding 600 ˚ C.
Inventors:
TANEIKE MASAKI (JP)
ABE FUJIO (JP)
ABE FUJIO (JP)
Application Number:
PCT/JP2002/003933
Publication Date:
February 27, 2003
Filing Date:
April 19, 2002
Export Citation:
Assignee:
NAT INST FOR MATERIALS SCIENCE (JP)
MITSUBISHI HEAVY IND LTD (JP)
TANEIKE MASAKI (JP)
ABE FUJIO (JP)
MITSUBISHI HEAVY IND LTD (JP)
TANEIKE MASAKI (JP)
ABE FUJIO (JP)
International Classes:
C21D6/00; C22C38/00; C22C38/02; C22C38/04; C22C38/22; C22C38/24; C22C38/26; C22C38/30; C22C38/32; C22C38/52; C22C38/54; (IPC1-7): C22C38/00; C21D6/00
Download PDF: