The combination of the austempered ductile iron mechanical properties strongly depend on the parameters used on the austempering cycle. On this study, the influence of austempering time and austenitizing temperature on the properties of a ductile iron were evaluated. A metallic bath of Zamak at 380°C was used as an austempering mean. A set of ductile iron blocks were austenitized at 900°C for 90 minutes and submitted to different austempering times in order to determine the best combination of microstructural and mechanical properties. After the definition of the time of austempering, the reduction of the austenitizing temperature was evaluated. The best combination of properties was obtained with austenitizing at 860°C and austempering during 60 minutes.
Resumo Este trabalho reporta a viabilidade de realizar o tratamento térmico de austêmpera, para obtenção de um Ferro Dúctil Austemperado (ADI), utilizando uma liga de Zn-Al-Mg-Cu, como meio de resfriamento e permanência em patamar, durante o processo de tratamento térmico. Por meio da obtenção da curva de resfriamento da liga Zamac 5, constatou-se a viabilidade de realização da austêmpera em temperaturas superiores a 380ºC. A partir de corpos de prova de ferro fundido nodular de matriz predominantemente perlítica, instrumentados e austenitizados a 870°C e 900°C, avaliou-se a taxa de resfriamento promovida pela liga Zamac 5, até a temperatura de 400°C. O tratamento mostrou-se eficiente, utilizando a liga como meio de austêmpera, sendo registradas taxas de resfriamento superiores a 6°C/s. A análise morfológica constatou a formação de ausferrita, sem a presença de perlita, caracterizando assim a formação do ADI. Palavras-chave: Austêmpera; Zamac; ADI; Ausferrita OBTAINMENT OF ADI BY AUSTEMPERING TREATMENT USING ZAMAK 5 BATH Abstract This work reports the feasibility of conducting austempering heat treatment to obtain an Austempered Ductile Iron (ADI), using a Zn-Al-Mg-Cu alloy, as means of cooling and sustaining the thermal arrest during the heat treatment process. By obtaining the alloy cooling curve, with a composition corresponding to Zamak 5, it was verified the feasibility of austempering at temperatures above 380ºC. From samples of nodular cast iron with predominantly perlite matrix, instrumented and austenitized at 870 °C and 900 °C, the cooling rate promoted by the Zamak 5 alloy was evaluated, until the temperature of 400 °C. The treatment was efficient, using the alloy as austempering medium, with cooling rates higher than 6 °C/s. The morphological analysis verified the formation of ausferrite, without the presence of perlite, characterizing the formation of ADI.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.