一种Nb-Ti微合金钢微合金碳氮化物析出行为的研究

Study on the Performance of Carbonitride Precipitation in Nb-Ti Microalloyed Steels

利用热模拟和TEM技术研究了Nb-Ti微合金钢中微合金碳氮化物的析出行为,研究结果表明,高温奥氏体区析出的微合金碳氮化物数量随变形量的增大而增加,尺寸随着变形温度的升高稍有增大。铁素体区析出的微合金碳氮化物尺寸比在形变奥氏体中析出的更为细小,数量随着保温时间的增加而增多,但尺寸变化不大;当温度较低的时候,微合金碳氮化物主要在位错线等晶内缺陷处析出。

The precipitation of carbonitrides in Nb Ti microalloyed steels has been investigated by using a combined technique of thermal simulation and transmission electron microscopy （TEM）. It is shown that increasing the deformation leads to an increase in the amount of microalloyed carbonitrides precipitated in the high temperature austenitic region. The austenite grain size increases slightly with elevated deformation temperature. The microalloyed carbonitride precipitated in the ferritic region is much finer than that precipitated in the deformed austenite and the amount goes higher with soaking time, while the size remains almost unchanged. At low temperature the microalloyed carbonitrides mainly precipitate at defects such as dislocation lines in grains.