Optimalizace délky izotermické transformace při výrobě izoterimcky zušlechtěné litiny s kuličkovým grafitem

Optimization in Dwell Length of ADI Isothermal Transformation

článek v časopise - ostatní, Jost

en

Austempered ductile iron (ADI) is usually obtained by isothermal heat treatment. Owing to its excellent mechanical as well as technological properties, ADI belongs among prospective structural materials. Recently it is applied also to castings for dynamically loaded machine details, e.g. gear and traversing wheels, crankshafts of motor-cars, vans and trucks, swivel pins, rail brakes and pressure pipes in oil industry. Microstructure and mechanical properties of ADI can be substantially influenced by the condition of heat treatment. While the austenitization conditions play only marginal role, the conditions of isothermal transformation, i.e. transformation temperature and the dwell at it, influence the resulting structure of ADI and consequently its mechanical properties very substantially

Izotermicky zušlechtěná tvárná litina, v současné době nazývaná ADI (austempered ductile iron), patří mezi perspektivní konstrukční materiály, zejména pro dynamicky namáhané strojní součásti. Její vlastnosti je možno ve velmi širokém rozsahu ovlivňovat podmínkami režimu tepelného zpracování. Zatímco podmínky austenitizace (teplota austenitizace 880 – 920 °C, výdrž na teplotě 1 – 3h) nehrají významnější roli, podmínky izotermické transformace, t.j. transformační teplota a doba výdrže na této teplotě, ovlivňují výslednou strukturu matrice ADI a tím i její mechanické vlastnosti zásadním způsobem

Austempered ductile iron (ADI) is usually obtained by isothermal heat treatment. Owing to its excellent mechanical as well as technological properties, ADI belongs among prospective structural materials. Recently it is applied also to castings for dynamically loaded machine details, e.g. gear and traversing wheels, crankshafts of motor-cars, vans and trucks, swivel pins, rail brakes and pressure pipes in oil industry. Microstructure and mechanical properties of ADI can be substantially influenced by the condition of heat treatment. While the austenitization conditions play only marginal role, the conditions of isothermal transformation, i.e. transformation temperature and the dwell at it, influence the resulting structure of ADI and consequently its mechanical properties very substantially

ADI, isothermal transformation, transformation dwell lenght, mechanical properties, fatigue properties

2003

25.11.2003

1429-6055

Zeszyty naukowe politechniki Opolskiej seria Mechanika

76

290

6