Comparison of microstructure and hardness between high-carbon and high-nitrogen martensites

Toshihiro Tsuchiyma, Kurato Inoue, Katsutoshi Hyodo, Daichi Akama, Nobuo Nakada, Setsuo Takaki, Tamotsu Koyano

Research output: Contribution to journalArticle


The microstructure and hardness of martensite in Fe-C and Fe-N alloys with up to 7.5 at% contents of carbon and nitrogen, respectively, were compared. Their difference in hardness was discussed based on four strengthening mechanisms. The martensitic structures of Fe-C and Fe-N alloys with equal contents of carbon and nitrogen, respectively, were nearly identical, except for the amount of retained austenite. Furthermore, Fe-C alloy was considerably harder than Fe-N alloy. This discrepancy gradually increased with carbon and nitrogen contents. The enhanced hardness of Fe-C alloy martensite was attributed to its higher dislocation density and the stronger pinning force of interstitial carbon atoms on dislocations.

Original languageEnglish
Pages (from-to)161-168
Number of pages8
Journalisij international
Publication statusPublished - Jan 1 2019


All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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