pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (22권2호 69-74)
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
Sug-Won Kim, Sang-Won Han, Ui-Jong Lee, Jin-Sung Park, Kee-Do Woo, Dong-Keun Lim
Chonbuk National University
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.
Heat treament cycle, Prequenching austernpering,Fatigue test, Preheating austempering, Fatigue life cycles, Fatigue strength