钒钛微合金化耐腐蚀弹簧钢连续冷却的相变规律

Phase transformation rule of V-Ti microalloyed corrosion resistant spring steel during continuous cooling

利用膨胀法结合金相-显微硬度法,在Gleeble-3500热模拟试验机上研究了钒钛复合耐腐蚀弹簧钢在变形与未变形条件下的连续冷却相变规律,并绘制了静态和动态连续冷却转变曲线(CCT曲线)。研究结果表明:同静态CCT曲线相比,动态CCT曲线整体向左上方移动,即变形对各相的转变有促进作用,铁素体消失的冷速由3.5℃/s提高到10℃/s,珠光体消失的冷速由7℃/s提高到10℃/s;随着冷却速度的增加,珠光体片层间距减小,显微硬度值增大。

Phase transformation rule of corrosion resistant spring steel with or without deformation during continuous cooling was studied using a Gleeble-3500 thermal mechanical simulator by expansion method and metallography hardness method. In addition,static CCT curves and dynamic CCT curves were obtained. Experimental results show that the dynamic CCT curves shift to the left and upper compared with the static ones. That is to say,deformation promotes each phase transformation. The cooling rates for ferrite disappearance can increase from 3. 5 ℃ / s to 10 ℃ / s,for pearlite disappearance increase from 7 ℃ / s to 10 ℃ / s. With the increasing of cooling rates,the lamellar spacing of pearlite decreases and Vickers hardness of pearlite increases.