| Austempered ductile cast iron (ADI) has emerged as an important engineering material in recent years because of its excellent mechanical properties.; In this investigation, one batch of a nodular or ductile cast iron samples with predominantly pearlitic as-cast structure was processed by conventional austempering process at three different temperatures. Another batch of ductile cast iron samples were austempered at three different temperatures as before and then tempered. It was observed that by tempering at 900°F for 2 hours, a fully ferritic structure ADI (austenite free) can be developed. For comparison purpose, microstructures, mechanical properties, fractography, thermal conductivity and resistivity of these samples were evaluated.; X-ray data confirmed that this ADI is totally austenite free. It was observed that the thermal conductivity and resistivity of the tempered samples is more compared to the non tempered samples at that particular austempering temperature. At 500°F austempering temperature, there is no change in mechanical properties even after tempering at 900°F for 2 hours. (Abstract shortened by UMI.)... |
