Two-Sublattice Thermodynamic Model on Carbonitride Precipitation in Microalloyed Steels Bearing Nb-V-Ti  

作　　者：XIANG Song 1,3,LIU Guo-quan 2 (1.School of Materials and Metallurgy,Guizhou University,Guiyang 550003,Guizhou,China 2.School of Materials Science and Engineering,University of Science and Technology,Beijing,Beijing 100083,China 3.The Key Laboratory for Mechanical Behavior and Microstructure of Materials,Guizhou Province,Guiyang 550003,Guizhou,China) 

出　　处：《Journal of Iron and Steel Research International》2011年第S1期271-277,共7页

基　　金：the National Natural Science Foundation of China (No.50901022,51071019 and 50271009);the Vanadium International Technical Committee

摘　　要：Based on the two sublattice model of the regular solution,one being metal atom sublattice and another being interstitial atom sublattice,a thermodynamic model for the precipitates of niobium carbonitride,vanadium carbonitride and titanium carbonitride was established to study the starting-temperature of precipitates and the austenite compositions at given temperature in a low carbon steel.The calculation results show that starting-temperature of the precipitation of niobium carbonitride,vanadium carbonitride and titanium carbonitride are 1100℃,920℃ and 1340℃,respectively,the mole fraction of carbonitride precipitates is 8.65×10-4 in the 0.053C-0.0028N-1.28Mn-0.008S-0.031Al-0.046Nb-0.008Ti0.029V-Fe steel.When the N content is from 0.0028% to 0.0056%,the starting-temperature of the precipitation of the titanium carbonitride changes from 1340℃ to 1430℃.And the C content is from 0.053% to 0.07%,the startingtemperature of the precipitation of the titanium carbonitride hardly changes,but the atomic fraction of niobium in the carbonitride obviously increases.Based on the two sublattice model of the regular solution,one being metal atom sublattice and another being interstitial atom sublattice,a thermodynamic model for the precipitates of niobium carbonitride,vanadium carbonitride and titanium carbonitride was established to study the starting-temperature of precipitates and the austenite compositions at given temperature in a low carbon steel.The calculation results show that starting-temperature of the precipitation of niobium carbonitride,vanadium carbonitride and titanium carbonitride are 1100℃,920℃ and 1340℃,respectively,the mole fraction of carbonitride precipitates is 8.65×10-4 in the 0.053C-0.0028N-1.28Mn-0.008S-0.031Al-0.046Nb-0.008Ti0.029V-Fe steel.When the N content is from 0.0028% to 0.0056%,the starting-temperature of the precipitation of the titanium carbonitride changes from 1340℃ to 1430℃.And the C content is from 0.053% to 0.07%,the startingtemperature of the precipitation of the titanium carbonitride hardly changes,but the atomic fraction of niobium in the carbonitride obviously increases.

关 键 词：microalloyed steel CARBONITRIDE PRECIPITATION two sublattice model THERMODYNAMICS 

分 类 号：TG142.33[一般工业技术—材料科学与工程]