中碳铌微合金钢的应变诱导析出行为

Strain-Induced Precipitation Behavior in Medium-Carbon Nb Microalloyed Steels

通过应力松弛法验证了修正后的DS析出模型,得到了中碳铌微合金钢的应变诱导析出规律,结果表明:修改后的DS模型由于考虑了Si、Mn元素对碳氮化物应变诱导析出的影响,得到的PTT曲线与试验测得的曲线基本吻合,可用于Si、Mn含量较高的铌微合金钢应变诱导析出行为的预测;对于本试验用钢,PTT曲线具有典型的"C"型特征,鼻子温度在900℃左右,并且,随着应变速率的增大,PTT曲线左移,析出孕育期缩短。

The modified DS precipitation model was verified by stress relaxation method,and the strain induced precipitation behavior of medium-carbon Nb microalloyed steel was obtained.The results show that the calculated precipitation-time-temperature（PTT）diagrams are in good agreement with experimental results obtained from isothermal stress relaxation,because the effects of Si and Mn on the precipitation kinetics of Nb carbonitride added to the DS equation;The shape of PTT is typical C curve,and the nose temperature is about 900 ℃ for the tested steel,strain rate accelerates the precipitation kinetics and shifts the PTT diagrams leftside.