Effects of Special Heat Treatments and Alloying Elements on the Microstructures and Mechanical Charateristics of ADI

ADI의 미세조직과 기계적 특성에 미치는 특수열처리 및 합금원소의 영향

  • Kim, Sug-Won (Division of Advanced Materials Engineering, Chonbuk National University, Research Center of Advanced Materials Development(RCAMD)) ;
  • Han, Sang-Won (Division of Advanced Materials Engineering, Chonbuk National University, Research Center of Advanced Materials Development(RCAMD)) ;
  • Lee, Ui-Jong (Division of Advanced Materials Engineering, Chonbuk National University, Research Center of Advanced Materials Development(RCAMD)) ;
  • Park, Jin-Sung (Division of Advanced Materials Engineering, Chonbuk National University, Research Center of Advanced Materials Development(RCAMD)) ;
  • Woo, Kee-Do (Division of Advanced Materials Engineering, Chonbuk National University, Research Center of Advanced Materials Development(RCAMD)) ;
  • Lim, Dong-Keun (Division of Advanced Materials Engineering, Chonbuk National University, Research Center of Advanced Materials Development(RCAMD))
  • 김석원 (전북대학교 신소재공학부, 신소재개발연구센터) ;
  • 한상원 (전북대학교 신소재공학부, 신소재개발연구센터) ;
  • 이의종 (전북대학교 신소재공학부, 신소재개발연구센터) ;
  • 박진성 (전북대학교 신소재공학부, 신소재개발연구센터) ;
  • 우기도 (전북대학교 신소재공학부, 신소재개발연구센터) ;
  • 김동건 (전북대학교 신소재공학부, 신소재개발연구센터)
  • Published : 2002.04.20

Abstract

The effects of heat treatments and alloying elements on the microstructure and mechanical charaterisitics of specially austempered ADIs containing alloying elements such as Cu, Mo and Ni were investigated. To compare with the effect of conventional and normal(CN) austempering treatment, two kinds of special austempering treatments which are those with pre-quenching and pre-heating were conducted. The hardness and uniaxial fatigue tests were carried out to evaluate the mechanical charateristics. The hardness of ADI treated by CN heat cycles was higher than those of other ADIs. Cu added ADI (Cu-ADI) tempered at 400 after austenitizing exhibited the highest fatigue life cycles. While austempering after prequenching makes the austenite with high carbon stable, which resulted in transformation to highly strengthened bainites from the carbon enriched austenite phases during tempering. The high carbon enriched banites is considered to improve the fatigue strength.

Keywords

References

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