QUANTIFYING THE EFFECT OF Nb AND Mo ON TRANSFORMATION PRODUCTS USING ADVANCED EBSD ANALYSIS
Nb is the key element in thermo-mechanically controlled processing of high strength low alloy steels due to its enormous effect on delaying the recrystallization of deformed austenite.Similarly Nb in solution delays the austenite-ferrite transformation,thereby further promoting microstructural refinement and high strength at low carbon levels.Mo is frequently added to further increase the hardenability.The aim of this study is to quantitatively describe the synergistic effect of Nb and Mo on the microstructure evolution in HSLA steels during austenite decomposition.Continuous cooling transformation studies on steels with varying Nb and Mo levels were conducted and the resulting microstructures were characterized with EBSD.The addition of both Nb and Mo lowers the transformation temperature and promotes the formation of complex bainitic transformation products that have been distinguished and categorized based on their orientation relationship with the parent austenite grain.In particular,microstructure refinement has been quantified in terms of high angle grain boundary length per unit area.In addition the fraction and size of carbon-rich martensite/austenite constituents have been characterized and correlated with the bainitic structure as a function of the transformation temperature.
Nb-Mo steels Continuous cooling transformation EBSD Bainite Martensite/Austenite
Jennifer M.Reichert Matthias Militzer
The Centre for Metallurgical Process Engineering,The University of British Columbia,309-6350 Stores Rd.,Vancouver,BC,Canada V6T1Z4
国内会议
杭州
英文
143-149
2015-11-11（万方平台首次上网日期，不代表论文的发表时间）