A Study on the Rare-earth Boronizing Treatment of STD 61 Steel

열간금형용강의 희토류붕화처리에 관한 연구

  • Kim, C.C. (Faculty of Metallurgical Science and Engineering, Pukyong National University) ;
  • Youn, J.H. (Dep. of Metallurgical Science and Engineering, Changwon National University) ;
  • Jang, Y.S. (Faculty of Mechanical system, Koyungnam College of Information and Technology)
  • 김창규 (부경대학교 재료공학부) ;
  • 윤재홍 (창원대학교 재료공학과) ;
  • 장윤석 (경남정보대학 기계시스템공학부)
  • Received : 2000.03.15
  • Published : 2000.07.30

Abstract

The boronizing effects of STD 61 steel have been studied on the micro structure and hardness. The STD 61 Steel was soaked in molten salt, consisted of KCl, $BaCl_2$, NaF, $B_2O_3$, FeB, and Ce, at various temperatures and times. The boronizing conditions for the peak hardness were the temperature range of $900^{\circ}C$ to $950^{\circ}C$ for 5 hr and that of $1000^{\circ}C$ for 3 hr, respectively. Four boride layers such as FeB, $Fe_2B$, ${\alpha}$ and matrix layer surface were observed from the microscopic surface examination. The thickness of boride layer was increased by increasing the boronizing time and the temperature. The structure of boride layer was tooth shape.

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