摘要
在不同变形条件(变形温度1000~1150℃、应变速率0.01~5 s^(−1)、道次间隔时间5~30 s)下对18CrNiMo7-6齿轮钢进行单道次和双道次热压缩试验,研究了该钢的动态再结晶(DRX)和亚动态再结晶(MDRX)行为,建立了DRX和MDRX动力学模型,对不同变形条件下的DRX和MDRX体积分数进行预测,分析了预测精度。结果表明:在热变形过程中,该钢的DRX体积分数随着变形温度的升高和应变速率的降低而增大,MDRX体积分数随着变形温度和应变速率的提高以及道次间隔时间的延长而增大。构建的DRX和MDRX动力学模型预测精度较高,前者预测的DRX体积分数曲线与由流变曲线计算得到的结果的决定系数大于0.9,后者预测的MDRX体积分数与由2%应力补偿法获得的结果的平均相对误差为6.619%。通过Zener-Hollomon参数方程得到的DRX和MDRX激活能分别为47.381,291.802 kJ·mol^(−1)·K^(−1)。
The dynamic recrystallization(DRX)and metadynamic recrystallization(MDRX)behaviors of 18CrNiMo7-6 gear steel were studied by single-pass and double-pass thermal compression tests under different deformation conditions(deformation temperature at 1000‒1150℃,strain rate of 0.01‒5 s^(−1),pass interval time of 5‒30 s).The dynamic models of DRX and MDRX were established to predict DRX and MDRX volume fractions of the steel under different thermal deformation conditions,and the prediction accuracy was analyzed.The results show that during thermal deformation,the DRX volume fraction increased with the increase of deformation temperature and the decrease of strain rate,and the MDRX volume fraction increased with the increase of deformation temperature,strain rate and pass interval time.The prediction accuracy of DRX and MDRX dynamic models was high.The determination coefficient of the DRX volume fraction curves predicated by the former and the results obtained by the flow curves was greater than 0.9;the average relative error between the MDRX volume fraction by the latter and the results obtained by the 2%stress compensation method was 6.619%.The activation energies of DRX and MDRX obtained by Zener-Hollomon parametric equation for this steel were 47.381,291.802 kJ·mol^(−1)·K^(−1),respectively.
作者
张肖佩佩
吴晓东
周少荣
ZHANG-XIAO Peipei;WU Xiaodong;ZHOU Shaorong(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2024年第11期29-36,共8页
Materials For Mechanical Engineering
基金
国家重点研发计划项目(2020YFB2008100)。
