Journal of the Korean Society for Heat Treatment (열처리공학회지)

The Korean Society for Heat Treatment (한국열처리공학회)
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Microstructural Characterization in Partially Austenitized and Isothermally Transformed 1.0C-1.5Cr Bearing Steels

부분 오스테나이트화 후 항온 변태한 1.0C-1.5Cr 베어링강의 미세조직 특성

  • Yoon, Dong-Joo (Dept. of Iron & Metallurgical Eng., Hanlyo Sanup University) ;
  • Choi, Byung-Young (Department of Metallurgical Engineering, Chonbuk National University)
  • 윤동주 (한려산업대학교 제철금속학과) ;
  • 최병영 (전북대학교 공과대학 금속공학과)
  • Published : 1996.03.31
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Abstract

Metallographic observation was carried out by scanning and transmission electron microscopy to evaluate microstructural characteristics of partially austenitized and isothermally transformed 1.0C-1.5Cr bearing steel. It was observed that lower bainite formed in the local region of specimen partially austenitized and isothermally held at $250^{\circ}C$ for 1/3 hr and formed in almost all area of the specimen isothermally held at $250^{\circ}C$ for 2 hrs. Lower bainitic carbides with midrib was also observed in the specimen partially austenitized and isothermally held at $250^{\circ}C$ for 4 hrs. Midrib was nearly carbide-free region and thicker in the vicinity of spherical carbides than the other region. Lengthening speed of lower bainitic carbides was remarkabey increased at isothermal holding time ranging from 2 hrs to 4 hrs.

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