摘要
利用差示扫描量热分析法(DSC)研究了淬火态轻质Fe-15Mn-10Al-0. 3C(质量分数,%)钢在升温过程中κ-碳化物的析出行为。由DSC曲线可以发现,δ-铁素体中淬火时形成的DO3相,先转变为L1_2相,再转变为κ-碳化物。利用JMAK方法计算了δ-铁素体中κ-碳化物的析出动力学和奥氏体分解动力学。计算结果表明:DO3相向L1_2相转变的激活能为145. 25 kJ/mol,L1_2相向κ-碳化物转变的激活能为81. 18 k J/mol。此外,试验钢经600℃时效30 s后,δ-铁素体的硬度最高,此时δ-铁素体中κ-碳化物的相对体积分数约为20%。
Precipitation behavior of κ-carbides in the quenched lightweight Fe-15 Mn-10 Al-0. 3 C( mass fraction,%) steel during heating process was studied by differential scanning calorimetric( DSC) techniques. It was found from the DSC measured curves that the DO3 phase formed in quenching in δ-ferrite firstly transformed into L1_2 phase and then into κ-carbide. The precipitation kinetics of κ-carbide in δ-ferrite and the austenite decomposition kinetics were calculated using the JMAK equation. The calculated results showed that the activation energy of DO3 phase transition into L1_2 phase and L1_2 phase transition into κ-carbide were 145. 25 kJ/mol and 81. 18 kJ/mol,respectively. Besides,the hardness of δ-ferrite was the highest in test steel after aging at 600 ℃for 30 s,and the relative volume fraction of κ-carbides in δ-ferrite was about 20%.
引文
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