热变形奥氏体CCT曲线实用化修正研究

探讨了工艺参数对动态CCT曲线位置影响,分析采用热模拟方式测定的热变形奥氏体CCT曲线在实际应用中出现偏差的原因。结合实验及现场对变形奥氏体连续冷却规律的实测,介绍了修正动态CCT曲线的方法,该方法利用实测连续的冷却过程中相变潜热释放引起轧件温降速度变化,采用切线法获得实际工况下的相变开始和结束温度以及相变持续时间,修正后的动态CCT曲线中相变特征点更贴近生产实际。采用修正后的CCT曲线相变温度进行组织性能预测,预测结果与实测结果误差在5%以内。

THE PRACTICAL CORRECTION RESEARCH ON CCT CURVES OF HOT DEFORMATION AUSTENITE

The effect of technical parameters on the position of dynamic CCT diagram was discussed,the reason for the deviation in the application of the heat simulated CCT curves of hot deformation austenite was analyzed.On the basis of the actual measurements,a method of correcting the dynamic CCT was introduced by measuring the temperature rising of rolling piece caused by the releasing of transformation latent heat during continuous cooling,the phase transformation temperature at starting and ending as well as the duration time in production reality were obtained by tangential method.The phase transformation characteristic point of the corrected dynamic CCT curves was more close to the production practice.The phase transformation temperature of corrected dynamic CCT curve was used to predict the structural property,the error of predicted results was within 5% comparing to the practical measurement.