轧制工艺对Ti微合金化马氏体钢力学性能的影响

Effect of Hot Rolling Process on Mechanical Properties of Ti-Microalloyed Martensitic Steel

通过采用扫描电镜、透射电镜、X射线衍射以及相分析等手段来观察组织的微观结构和对析出相的验证,研究轧制温度对轧态Ti微合金化马氏体钢强度的影响.研究结果表明,通过降低轧制温度可以明显提高含Ti马氏体钢的屈服强度,这主要是因为当轧制温度从1100℃降低到950℃过程中,形变诱导析出大量的TiC析出相,随着轧制温度的降低,析出相数量明显增加,并且平均尺寸也逐渐变小.马氏体中大量存在的1～20 nm范围的析出相可以起到明显的析出强化作用.

The microstructures and second precipitated particles were examined by scanning electron microscopy （SEM）, transmission electron microseopy（TEM）, X-rays diffraction and phase analysis method. The effect of the hot rolling temperature on the strength of a rolled Ti-microalloyed martenstic was investigated. It is found that the yield strength of the martensitie steel is significantly improved by decreasing the hot rolling temperature. This is mainly caused by a large amount of TiC precipitations induced by deformation when the temperature is dropping from 1 100℃ to 950℃ during the rolling process. Moreover, as the rolling temperature is lowered, the amount of the precipitations is increased significantly, and the average size also gradually becomes smaller. The precipitations of about 1-20 nm in the martensite matrix obviously have the precipitation strengthening effect.