pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (30권2호 60-65)
The Effects of Austempering Heat Treatment on the Processing Window and Mechanical Properties in Cast and Hot-rolled Fe-0.7wt%C-2.3wt%Si-0.3wt%Mn Steel
주조 및 열간 압연된 Fe-0.7wt%C-2.3wt%Si-0.3wt%Mn 강의 프로세싱 윈도우와 기계적 성질에 미치는 오스템퍼링 조건의 영향 비교
Je-Young Son, Dong-Chan Hwang, Jae-Joo Choi, June-Hwan Song, Ji-Hun Kim*, Won-Bae Kim**, Byung-Joon Ye
Kyungpook National University, *Small and Medium Business Corporation, **Korean Technology Credit Gurantee Fund
In this study, we investigate the effects of austempering heat treatment on the processing window and mechanical properties in cast and hot-rolled Fe-0.7 C-2.3 Si-0.3 Mn steel. Each specimens were austenitised at 900oC for 7 min, and austempered at 260oC, 320oC, and 380oC for the various periods of time from 2 min to 240 min. After heat treatment, the evaluation of stage I and stage II as performed by optical metallography, XRD, hardness test. Both cast and hot rolled specimens had similar processing window. So grain size effect is not important to the austempered high carbon high silicon cast steel. When the austempering temperature was 260oC, the microstructure consisted of the lower ausferrite while the upper ausferrite structure was formed at 380oC. As the austempering temperature increases from 260 to 380oC, the strength and hardness decreased, elongaton and volume fraction of austenite increased. In addition, there was no change of mechanical properties between cast and hot-rolled specimens.
Casting, Hot rolling, Austempering, Austempered Ductile Cast Iron, Heat Treatment, Ausferrite.
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