Effect of Thermomechanical Process on Mechanical Property and Microstructure of 9Cr-1Mo Steel

열간가공이 9Cr-1Mo강의 기계적 성질과 미세조직에 미치는 영향

  • Kim, Jun-Hwan (SFR Fuel Cladding Development, Korea Atomic Energy Research Institute) ;
  • Baek, Jong-Hyuk (SFR Fuel Cladding Development, Korea Atomic Energy Research Institute) ;
  • Han, Chang-Hee (SFR Fuel Cladding Development, Korea Atomic Energy Research Institute) ;
  • Kim, Sung-Ho (SFR Fuel Cladding Development, Korea Atomic Energy Research Institute) ;
  • Lee, Chan-Bock (SFR Fuel Cladding Development, Korea Atomic Energy Research Institute) ;
  • Na, Kwang-Su (Technical Research Center, Hyundai Steel Company) ;
  • Kim, Seong-Ju (Technical Research Center, Hyundai Steel Company)
  • 김준환 (한국원자력연구원 SFR 핵연료 피복관 개발) ;
  • 백종혁 (한국원자력연구원 SFR 핵연료 피복관 개발) ;
  • 한창희 (한국원자력연구원 SFR 핵연료 피복관 개발) ;
  • 김성호 (한국원자력연구원 SFR 핵연료 피복관 개발) ;
  • 이찬복 (한국원자력연구원 SFR 핵연료 피복관 개발) ;
  • 나광수 (현대제철 기술연구소) ;
  • 김성주 (현대제철 기술연구소)
  • Received : 2009.03.09
  • Published : 2009.10.25

Abstract

Thermomechanical processes were carried out to evaluate their effects on the mechanical and the microstructural property of a ferritic-martensitic steel. Modified 9Cr-1Mo steels were hot-rolled at a temperature of either $780^{\circ}C$ or $850^{\circ}C$ after normalizing at $1050^{\circ}C$ and then were air-cooled. Continuous annealing at $850^{\circ}C$ for 2 hours immediately after the hot rolling was also performed and they were compared to the specimens without thermomechanical process. The result showed that there were little differences between the hot rolled specimens in terms of the precipitation density and size. However, V content inside the MX precipitates increased in the case of the specimen rolled at $850^{\circ}C$. The application of the continuous annealing induced coarsening of the Nb-rich MX precipitation as well as an increase in the amount of V-rich MX precipitation, which is expected to enhance high temperature mechanical properties of the ferritic-martensitic steel.

Keywords

Acknowledgement

Grant : 핵연료 핵심기반기술 개발

Supported by : 교육과학기술부

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