用新装置测定DP590钢的凝固相转变曲线

Determine of the Solidifi cation Phase Transition Curve of DP590 Steel with New Device

利用自行开发设计的高温凝固相转变测定装置,研究了DP590钢在不同冷速下的高温凝固相转变过程,得到了凝固过程中液相（L）到高温铁素体（δ）再到奥氏体（γ）的相变温度,并绘制了该钢的凝固相转变（SPT）曲线。结果表明：当冷速为0.006℃·s-1时,该钢δ相转变开始温度在1 520~1 535℃之间,结束温度在1 490℃左右;冷速增至0.33℃·s-1时,δ相转变开始温度降至1 510~1 520℃之间,结束温度在1 480~1 490℃之间;γ相转变开始温度为1 460℃之上,结束温度在1 435℃以下;随着冷速的增大,相转变模式会发生变化,相图会向下移动,各相变反应的温度区间减小。

A self-designed experimental apparatus was employed to study the high temperature solidifi cation phase change process of DP590 steel at the different cooling rate and get the phase-transition temperature from liquid phase（L） to high temperature ferrite phase（δ） then to austenite phase（γ）. In addition, the solidifi cation phase transition（SPT） curves of DP590 steel were plotted. Results show that when cooling rate was 0.006 ℃ ·s-1, the beginning temperature of δ phase transition was between 1 520 ℃ and 1 535 ℃, the fi nishing temperature of δ phase transition was about 1 490 ℃. As the cooling rate reached to 0.33 ℃ ·s-1, the beginning temperature of δ phase transition was between 1 510 ℃ and 1 520 ℃, the fi nishing temperature of δ phase transition was between 1 480 ℃and 1 490 ℃. The beginning temperature of γ phase transition was above 1 460 ℃, the fi nishing temperature of γphase transition was below 1 435 ℃. The phase transition mode changed, the phase diagram moved down, and the temperature interval of phase reaction decreased, with increasing the cooling rate.