Mechanical properties and structure of austempered ductile iron -ADI

• Autorzy: Kaczorowski M. , Krzyńska A.
• Języki publikacji: EN

Abstrakty

EN

The results of experimental study of austempered ductile iron are presented. The aim of the investigations was to look closer into the structure – mechanical properties relationships of this very attractive cast material. The experiment was carried out with 500 7 grade ductile iron, which was austempered using different parameters of heat treatment. The specimens were first solution treated 1 hour in 910°C and then isothermally quenched for different time in silicon oil bath of temperature 275, 325, 300 and 350°C. The mechanical properties heat treated specimens were tested in tensile to evaluate yield stress R_e, 0.2, tensile strength R_m and elongation A_10. Additionally hardness of heat treated samples was measured using Brinell-Rockwell hardness tester. Structure of the specimens was studied either with conventional metallography, scanning (SEM) and transmission (TEM) electron microscopy. It followed from the study that conventional grade ductile iron enabled to produce both low and high strength ADI, depend on heat treatment parameters. As expected the low temperature isothermal quenching produced higher strength ADI compare to the same ductile iron but austempered at 350°C. It was discovered however, that low yield strength ADI obtained for short time quenching at 275°C exhibited high strengthening effect while strained in tensile. So it was concluded that this had to by cause by large amount of untransformed austenite, which FCC lattice is characterized by high strengthening coefficient.

Słowa kluczowe

EN

ADI; austempered ductile iron (ADI); heat treatment parameters; structure; properties

PL

ADI; żeliwo sferoidalne; obróbka cieplna; właściwości mechaniczne

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2007
• Tom: Vol. 7, iss. 1
• Strony: 161--166
• Opis fizyczny: Bibliogr. 15 poz., rys.

Twórcy

autor

Kaczorowski M.

autor

Krzyńska A.

• Institute of Mechanics and Design, Faculty of Production Engineering, Warsaw University of Technology, ul. Narbutta 85, 02-524 Warszawa

Bibliografia

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