Effect of Nb addition on Z-phase formation and creep strength in high-Cr martensitic heat-resistant steels

Kyu Ho Lee, Sung Min Hong, Jae Hyeok Shim, Jin Yoo Suh, Joo Youl Huh, Woo Sang Jung

Research output: Contribution to journalArticle

18 Citations (Scopus)


The effect of Nb addition on the creep strength of high-Cr martensitic heat-resistant steel was investigated at temperatures ranging from 839 to 894 K. The short-term creep properties were improved by Nb addition due to the enhanced MX precipitation. However, Nb addition deteriorated the steel's long-term stability resulting in an even shorter creep-rupture life than the original alloy. Onset of the accelerated degradation in Nb-containing steel was attributed to the gradual formation of Z-phase at the expense of M<inf>2</inf>N precipitates during creep exposure.

Original languageEnglish
Pages (from-to)79-84
Number of pages6
JournalMaterials Characterization
Publication statusPublished - 2015 Apr 1



  • Creep strength
  • Heat-resistant steels
  • Precipitation
  • XRD
  • Z-phase

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Science(all)
  • Condensed Matter Physics

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