Ti-Mo微合金钢中Mo对Ti(C,N)在奥氏体中析出量的影响

根据热力学相关理论,计算了铁基中Ti和Mo的相互作用系数.结合相关固溶量理论计算方法,对含不同量Mo和Ti的Ti-Mo微合金钢中Ti(C,N)在800℃到1300℃的奥氏体温度区固溶析出量进行了理论计算.分析计算结果发现:Mo可降低Ti在铁基中的活度,抑制Ti的析出,但影响较小,影响程度随着温度的升高而减小;Ti含量相同时,影响程度随Mo含量的增大而增大;Mo含量相同时,影响程度随Ti含量的增大出现先增大后减小的现象.最后,与相关实验数据进行对比分析认为:Ti/C原子数比约为0.5时微合金钢力学性能最好,此时Mo含量对Ti(C.N)析出量的影响最大.

Effect of Mo on the amount of Ti(C,N) precipitated from austenite in Ti-Mo micro-alloy steel

Activity interaction coefficients between elements Ti and Mo in iron-based systems were estimated on the basis of the thermodynamical theory. The solubility of Ti, C and N in austenite of Ti-Mo micro-alloy steel from 800 to 1300℃ was theoretically calculated at different Ti and Mo contents. Mo can decrease the activity of Ti in iron-based systems and restrain the precipitation of Ti, but its influence is little. The influence degree decreases with the rise of temperature. When the Ti content is constant, the influence degree heightens with the increase of Mo content in the steel. But when the Mo content is constant, the influence strengthens firstly and then weakens with the increase of Ti content in the steel. Finally, the calculated results were compared with experimental data. It is indicated that when the atomic ratio of Ti/C is about 0.5, the mechanical properties of the steel are the best and the Mo content has the greatest impact on the precipitation of Ti(C,N).