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IRON-CHROMIUM-ALUMINUM-BASED OXIDE DISPERSION STRENGTHENED STEEL AND METHOD FOR PRODUCING SAME

Foreign code F160008881
File No. (S2015-0732-N0)
Posted date Oct 25, 2016
Country WIPO
International application number 2016JP056402
International publication number WO 2016140258
Date of international filing Mar 2, 2016
Date of international publication Sep 9, 2016
Priority data
  • P2015-039891 (Mar 2, 2015) JP
Title IRON-CHROMIUM-ALUMINUM-BASED OXIDE DISPERSION STRENGTHENED STEEL AND METHOD FOR PRODUCING SAME
Abstract [Problem] To provide: an iron-chromium-aluminum-based oxide dispersion strengthened steel which can exhibit excellent high-temperature strength even at high temperatures of 1000°C or higher and which does not undergo the deterioration of oxidation resistance; and a method for producing the steel.
[Solution] An oxide dispersion strengthened steel 1 which has an aluminum oxide coating film 2 formed on a surface thereof and in which a yttrium-zirconium composite oxide 3 is dispersed, wherein excess oxygen that is oxygen existing in the oxide dispersion strengthened steel 1 excessively more than the amount required for forming yttrium oxide is contained at a molar ratio of 2 or more relative to the amount of zirconium.
Outline of related art and contending technology BACKGROUND ART
Oxide dispersion strengthened (ODS: Oxide Dispersion Strengthened) to steels, is MA956 or PM2000. PM2000 Chemical moiety Fe-19Cr-5.5Al-0.5Ti-0.5Y2 O3 (wt%) and, chemical moiety MA956 Fe-20Cr-4.5Al-0.5Ti-0.5Y2 O3 (wt%) and, both of ferrite steel. Dispersion strengthened steel oxide, aluminum oxide (alumina) by the addition of aluminum (scale) formed on the surface of the coating and thus, excellent oxidation resistance is known.
However, the above-mentioned oxide dispersion strengthened steel, has been added separately, yttrium oxide (Y2 O3) reacts with, a complex oxide of yttrium and aluminum is formed. For this reason, the number of coarse oxide particles density is decreased, which causes an increase in dispersal intervals for, based on the high temperature and provide dispersion strengthening is a problem that a strength is lowered.
In order to solve this problem, the inventors of the present invention, combined addition of 0.4-1.0 wt % zirconium with aluminum oxide on the dispersion strengthened alloy steel was developed (Patent Document 1). This oxide dispersion strengthened alloy according to the steel, aluminum and yttrium oxide is not react with the zirconium, yttrium and zirconium complex oxide is generated. For this reason, the number of oxide particles in a size reduction and increasing the density, and provide dispersion strengthening is effectively achieved and the high temperature strength is improved. In addition, yttrium oxide does not react with the aluminum, the surface of aluminum oxide to form the coating, which is also excellent in oxidation resistance as compared with the effect.
Scope of claims (In Japanese)[請求項1]
表面に酸化アルミニウムの被膜が形成されているとともに、内部にイットリウムとジルコニウムとの複合酸化物が分散されている酸化物分散強化型鋼であって、前記酸化物分散強化型鋼中で酸化イットリウムを形成する以上に存在する酸素である過剰酸素が、前記ジルコニウムに対するモル比で2以上含有されている、鉄-クロム-アルミニウム系酸化物分散強化型鋼。
[請求項2]
前記被膜にはジルコニウムが含有されていない、請求項1に記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼。
[請求項3]
質量%で、Crが12.0~23.0%、Alが5.0~8.0%、Tiが0.1~1.0%、Zrが0.2~1.0%、Y2O3が0.3~1.0%、残部がFeおよび不可避不純物からなる、請求項1または請求項2に記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼。
[請求項4]
前記過剰酸素の含有量は、ジルコニウムに対するモル比で4以上である、請求項1から請求項3のいずれかに記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼。
[請求項5]
1200℃で100時間酸化させたときの酸化増量が2.0mg/cm2以下である、請求項1から請求項4のいずれかに記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼。
[請求項6]
質量%で、Crが12.0~23.0%、Alが5.0~8.0%、Tiが0.1~1.0%、Zrが0.2~1.0%、Y2O3が0.3~1.0%、残部がFeおよび不可避不純物からなる原料粉末とともに、酸化物分散強化型鋼中で酸化イットリウムを形成する以上に存在する酸素である過剰酸素をジルコニウムに対するモル比で2以上添加し、機械的合金化処理する、鉄-クロム-アルミニウム系酸化物分散強化型鋼の製造方法。
[請求項7]
前記過剰酸素は、前記原料粉末の組成物の酸化物として添加される、請求項6に記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼の製造方法。
[請求項8]
前記酸化物は酸化鉄であり、質量%で0.24%以上添加される、請求項7に記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼の製造方法。
[請求項9]
前記過剰酸素の含有量は、ジルコニウムに対するモル比で4以上である、請求項6から請求項8のいずれかに記載の鉄-クロム-アルミニウム系酸化物分散強化型鋼の製造方法。
  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY
  • NIPPON NUCLEAR FUEL DEVELOPMENT CO., LTD.
  • Inventor
  • UKAI Shigeharu
  • OONO Naoko
  • HAYASHI Shigenari
  • OHTSUKA Satoshi
  • KAITO Takeji
  • KIMURA Akihiko
  • TORIMARU Tadahiko
IPC(International Patent Classification)
Specified countries National States: AE AG AL AM AO AT AU AZ BA BB BG BH BN BR BW BY BZ CA CH CL CN CO CR CU CZ DE DK DM DO DZ EC EE EG ES FI GB GD GE GH GM GT HN HR HU ID IL IN IR IS JP KE KG KN KP KR KZ LA LC LK LR LS LU LY MA MD ME MG MK MN MW MX MY MZ NA NG NI NO NZ OM PA PE PG PH PL PT QA RO RS RU RW SA SC SD SE SG SK SL SM ST SV SY TH TJ TM TN TR TT TZ UA UG US UZ VC VN ZA ZM ZW
ARIPO: BW GH GM KE LR LS MW MZ NA RW SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ RU TJ TM
EPO: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW KM ML MR NE SN ST TD TG
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