Intragranular ferrite was formed at inclusions in a vanadium microalloyed steel with excess amount of sulfur. The chemical composition of inclusions in the steel was analyzed by SEM-EDS. The inclusions were mainly com...Intragranular ferrite was formed at inclusions in a vanadium microalloyed steel with excess amount of sulfur. The chemical composition of inclusions in the steel was analyzed by SEM-EDS. The inclusions were mainly composed of MnS and aluminum oxides. The precipitation of MnS at aluminum oxides might result in Mn depletion, which, in turn, pro- motes the formation of intragranular ferrite. Optical and SEM observations and three- dimensional (3D) reconstruction demonstrated that intragranular ferrite was formed at inclusions. The morphology of intragranular ferrite changed with undercooling. At higher temperatures intragranular ferrite was nearly equiaxed whereas it was plate-like or lath-like at lower temperatures.展开更多
The evolution of degenerate ferrite in an Fe-0.28wt%C-3.0wt%Mo alloy isothermally reacted for 10ks at 20℃ below TTT diagram bay temperature have been revealed utilizing serial sectioning in conjunction with computer ...The evolution of degenerate ferrite in an Fe-0.28wt%C-3.0wt%Mo alloy isothermally reacted for 10ks at 20℃ below TTT diagram bay temperature have been revealed utilizing serial sectioning in conjunction with computer reconstruction and visualization. The degenerate ferrite is initially formed at prior austenite boundary and then grows toward grain interior rather than along the grain boundary. The degenerate morphology of ferrite may be attributed to repeated nucleation, growth and coalescence of adjacent ferrite crystals. The shape of individual ferrite crystals appears to be rod-like.展开更多
基金the Nationual Natural Science Foundation of China(No.50471107).
文摘Intragranular ferrite was formed at inclusions in a vanadium microalloyed steel with excess amount of sulfur. The chemical composition of inclusions in the steel was analyzed by SEM-EDS. The inclusions were mainly composed of MnS and aluminum oxides. The precipitation of MnS at aluminum oxides might result in Mn depletion, which, in turn, pro- motes the formation of intragranular ferrite. Optical and SEM observations and three- dimensional (3D) reconstruction demonstrated that intragranular ferrite was formed at inclusions. The morphology of intragranular ferrite changed with undercooling. At higher temperatures intragranular ferrite was nearly equiaxed whereas it was plate-like or lath-like at lower temperatures.
文摘The evolution of degenerate ferrite in an Fe-0.28wt%C-3.0wt%Mo alloy isothermally reacted for 10ks at 20℃ below TTT diagram bay temperature have been revealed utilizing serial sectioning in conjunction with computer reconstruction and visualization. The degenerate ferrite is initially formed at prior austenite boundary and then grows toward grain interior rather than along the grain boundary. The degenerate morphology of ferrite may be attributed to repeated nucleation, growth and coalescence of adjacent ferrite crystals. The shape of individual ferrite crystals appears to be rod-like.
