|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Material Design Approaches and Experiences IV
||Alloy Design for Promoting Creep Resistance of Austenitic Cast Steels for Exhaust Component Applications
||Yinhui Zhang, Mei Li, Larry Godlewski, Jacob Zindel, Qiang Feng
|On-Site Speaker (Planned)
To comply with stricter environmental and fuel consumption regulations, exhaust components for gasoline engines of automobiles are required to withstand exhaust gas temperatures as high as 1050 ℃. Thus, it is competitive to develop new cast steels with higher heat-resistance and durability than conventional materials. In this study, four Nb-bearing austenitic heat-resistant cast steels with variations of N/C ratio were developed to investigate the effect of C and N on the solidification path, particularly the formation mechanism of Nb(C,N) with different morphologies. Computational thermodynamic calculations via the Scheil-Gulliver module were performed to predict the solidification sequence of different phases. Directional solidification methods were carried out to examine the microstructural evolution in mushy zones. The compositional effect on the solidification sequence, phase transformation and Nb(C,N) morphology alternation will be discussed. The generated data and fundamental understanding will aid in microstructural optimizations of heat-resistant cast steels strengthened by primary and secondary precipitates.
||Planned: TMS Journal: JOM