X80管线钢中氮化物和碳化物析出热力学分析

Thermodynamic analysis of carbide and nitride precipitation in X80 pipeline steel

基于规则熔体理论和平衡反应基础,对连铸工序X80管线钢中碳化物、氮化物析出进行热力学分析,研究Ti、Nb及Al的碳化物、氮化物析出规律。结果表明,固液两相区,TiC0.005N0.995和TiN分别在1785K和1784K时开始析出;奥氏体相区,碳化物、氮化物析出先后顺序为NbC0.64N0.36、NbC、NbN、AlN、TiC,相应析出温度为1457、1404、1354、1267、1226K;γ→α相变过程中,TiC发生相间析出,Nb主要以NbC形式析出,AlN析出量较少。

Based on the regular solution theory and equilibrium reaction, the precipitation of carbides and nitrides in XS0 pipeline steel are thermodynamically analyzed and the precipitation condition and a- mount of Ti, Nb and A1 precipitates are investigated. The results show that, TIC0. 005N0. 0095 and TiN start to precipitate respectively at the temperatures of 1785 K and 1784 K in solid-liquid two- phase region; NbC0.64N0.36, NbC, NbN, A1N and TiC start to precipitate respectively at the tem- peratures of 1457, 1404, 1354, 1267 K and 1226 K; in the austenite to ferrite phase transition process, interphase precipitation of TiC will occur ; Nb element mainly precipitates in the form of NbC; and the precipitation amount of A1N is insignificant.