Effect of Microalloy Element on the Grain Coarsening Behavior of Q345 Steel
Austenite grain growth behavior of microalloy steels with addition of V,Nb or Al separately or two or three of the alloys together is studied in this article.The grain coarsening temperature from the grain size-temperature curves for different microalloy steels is defined according to ASTM grain size grade G=6.0.The results show that the grain coarsening temperature of Q345 steel alloyed with VN12 is about 40 ℃ higher than that of the Q345 steel treated by FeV.Compared to the treatment with Fe-Nb,the combined addition of Nb and V in the same Q345 steel has little influence on the grain coarsening temperature of the steel.Addition of trace Nb in the trace Al alloy Q345 steel does not show significant effect on the grain coarsening temperature.The resistance to austenite grain growth is:NbAlV.