Effect of Nb/W Ratio on Fe₂ (Nb, W) Laves Phase Formation in Fe-Cr-Al-Nb-W Alloy

• Yamagata Ryosuke

  Department of Materials Science, Graduate School of Engineering, Tohoku University

• Yoshimi Kyosuke

  Graduate School of Engineering, Tohoku University

Bibliographic Information

Other Title

• Fe-Cr-Al-Nb-W 合金中の Fe₂ (Nb, W) Laves 相形成に対する Nb/W 比の影響
• Fe-Cr-Al-Nb-W合金中のFe₂(Nb,W)Laves相形成に対するNb/W比の影響
• Fe-Cr-Al-Nb-W ゴウキン チュウ ノ Fe ₂(Nb,W)Lavesソウ ケイセイ ニ タイスル Nb/Wヒ ノ エイキョウ

Abstract

 Laves phases may be one of effective reinforcements at higher temperature for creep-resistant ferritic steels. In this study, the effect of Nb/W ratio on crystallization and precipitation behavior of Fe₂ (Nb, W) Laves phase was investigated for Fe-Cr-Al-Nb-W ferritic alloys. Fe-9Cr-6.5Al-10 (Nb, W) (at%) alloys were prepared by a conventional arc-melting technique. In the As-cast condition, the 10 at% Nb alloy was entirely composed of a eutectic phase of ferrite and Fe₂Nb. By substituting W for a part of Nb, the microstructure was changed to the combination of the primary ferrite and the eutectic of ferrite and Fe₂ (Nb, W). The microstructural change indicates that the composition shifted from eutectic to hypo-eutectic with increasing the W/(Nb+W) ratio in the alloy. For the 10 at% W alloy, there was no Laves phase in the as-cast microstructure. However, a number of Laves phase precipitates were observed inside grains after heat-treatment at 1000℃. The volume fraction of Laves phases decreased with increasing the W/(Nb+W) ratio in the alloy since the solubility limit of W in the ferritic matrix is higher than that of Nb at 1000℃. Therefore, the volume fraction and morphology are controllable by the Nb/W ratio in the Fe-Cr-Al-Nb-W alloy.<br>

Journal

• Journal of the Japan Institute of Metals and Materials

  Journal of the Japan Institute of Metals and Materials 80 (10), 646-654, 2016

  The Japan Institute of Metals and Materials

Keywords

• ferritic steel
• Laves phase
• eutectic reaction
• microstructure formation

Details

• CRID: 1390001206483155968
• NII Article ID: 130005264855
• NII Book ID: AN00187860
• DOI: 10.2320/jinstmet.j2016027
• ISSN: 18806880
• ISSN: 24337501
• ISSN: 00214876
• NDL BIB ID: 027685482
• Web Site: http://id.ndl.go.jp/bib/027685482
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I027685482
• Web Site: https://www.jstage.jst.go.jp/article/jinstmet/80/10/80_J2016027/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed