中锰Q&P钢连续退火过程碳元素分配行为

采用扫描电镜、X射线衍射等研究了连续退火工艺中退火、淬火和配分等关键过程参数对中锰Q&P钢碳元素分配行为的影响,并分析了相应工艺条件下残留奥氏体量与碳含量的关系。结果表明:两相区退火温度的提高会导致奥氏体中的碳含量下降,微观组织表现为奥氏体含量增加,渗碳体量减少;退火时间10~60 s时,随着退火时间的延长,奥氏体含量和碳含量急剧增加,60 s后基本保持稳定;试验条件下淬火温度对残留奥氏体及碳含量的影响不显著;配分温度350~500℃时,随着配分温度的提高,奥氏体含量和碳含量呈现先增加后减小的趋势,配分温度450℃时均达到最大值;延长配分时间,残留奥氏体含量呈现先减少后增大再减少的趋势,残留奥氏体中的碳含量先减小后增加。

Carbon distribution behavior of medium-manganese Q&P steel during continuous annealing

The effects of key process parameters, such as annealing, quenching and partition, on carbon distribution behavior of medium manganese Q&P steel during continuous annealing were studied by scanning electron microscopy(SEM) and X-ray diffraction(XRD). The relationship between retained austenite content and carbon content under the corresponding process conditions was analyzed. The results show that the increase of annealing temperature in two-phase region will lead to the decrease of carbon content in the austenite, the microstructure of which is the increase of austenite content and the decrease of carbon content. When the annealing time is 10-60 s, the austenite content and carbon content increase sharply with the increase of annealing time, and remain stable after 60 s. The effect of quenching temperature on retained austenite and carbon content is not significant under the experimental conditions. When the partition temperature is 350-500 ℃, with the increase of partition temperature, the amount of retained austenite and the content of carbon increase at first and then decrease, and reach the maximum at 450 ℃. With the increase of partition time, the amount of retained austenite decreases at first and then increases and then decreases, and the carbon content in the retained austenite decreases at first and then increases.