终轧温度及轧后冷却速度对Q460C钢组织和相变的影响

在Gleebl-1500热应力／应变模拟实验机上热压缩模拟Q460C含铌钢的轧制过程，并控制终轧温度和轧后冷却速度。通过观察金相组织和膨胀曲线研究控轧控冷对Q460C钢组织和相变的影响，分析了轧制过程中可能诱导其裂纹产生的原因。结果表明，Q460C钢组织分布不均、控轧控冷工艺不合理均可能造成其裂纹的产生，提高终轧温度可促进相变提前发生，而在较高终轧温度下，轧后冷却速度对Q460C钢组织变化的影响很小。

Influences of the finishing temperature and cooling rate on the organization and phase transformation of Q460C

The rolling process of Nb microalioyed steel Q460C was simulated by Gleehle-1500 at different finishing temperatures and post-rolling cooling rates, and the effects of controlled rolling and cooling schedule on the steel microstructure and phase change were analyzed by using optical microscopy technique and expansion curve. The possible causes of the cracks that appear on the steel during the rolling process are discussed. The results show that the uneven distribution in organization, unreason- able controlled rolling and cooling process may result in cracks, and raising the finish rolling temperature can make phase transitions happen ahead of time. But at a higher finish rolling temperature, post-rolling cooling rate has little effect on the organizational change.