Journal of Materials Research and Technology Journal of Materials Research and Technology
J Mater Res Technol 2018;7:198-202 DOI: 10.1016/j.jmrt.2017.08.011
Short Communication
Characteristics of tempering response of austempered ductile iron
Bingxu Wanga,, , Gary C. Barbera, Chuanlin Taoa, Xichen Sunb, Xu Ranc
a Oakland University School of Engineering and Computer Science, Rochester, MI, United States
b Fiat Chrysler Automobiles (FCA) North America LLC, Auburn Hills, MI, United States
c Changchun University of Technology, Changchun, China
Received 23 April 2017, Accepted 15 August 2017
Abstract

Austempered ductile iron (ADI) is produced by an isothermal heat treatment. Tempering is an effective method to increase the toughness and decrease the hardness of ADI. In the present research, the transformation of ADI was investigated after applying various tempering temperatures. The hardness of ADI samples with and without tempering was measured and the microstructure of ADI samples was analyzed by using metallographic optical microscopy. It was found that the ausferrite decomposed into dispersive cementite particles above a tempering temperature of 538°C. Thus, the tempering process for ADI must be carefully selected so that the excellent properties of ADI are not degraded.

Keywords
ADI, Tempering process, Hardness measurement, Phase transformation, Microstructure
J Mater Res Technol 2018;7:198-202 DOI: 10.1016/j.jmrt.2017.08.011