X80管线钢中Nb元素析出规律的研究

Research on Precipitated Rule of Nb in X80 Pipeline Steel

采用热力学模型计算了X80管线钢在不同温度下的相组成,相析出温度及Nb元素的析出规律;研究不同Nb含量对A3温度、各相析出温度和Nb析出规律的影响。计算结果表明,X80管线钢平衡态的析出相主要为Ti,Nb的碳氮化物、合金渗碳体、MnS、AlN、M7C3和Mo的碳化物。随Nb含量的增加,A3温度升高,Nb析出相的析出温度升高,而AlN相析出温度降低;在同一温度下Nb元素的析出量随Nb含量增加而升高。

Precipitated phases at the different temperature, the precipitated temperature and the precipitated rule of Nb in X80 pipeline steel were calculated by using the thermodynamic model, and the effect of the Nb content on A3 temperature, precipitated temperature and precipitated rule of Nb at different temperature was researched. The calculated results show that the main equilibrate precipitates in X80 pipeline steel are Ti, Nh carbides and nitrides, alloying cementite, MnS, AIN, M7C3 and Mo carbides. With increasing of Nb content, the A3 temperature, precipitated temperature of Nb precipitated phase and the precipitated content of Nb at the same temperature increase, while the precipitated temperature of AlN decreases.