CAJ | 학술논문

利用带有加热装置和同步组装系统的分离式Hopkinson压杆装置对纯铁进行宽温度范围(293～1 073 K)、高应变速率 (2 000～8 500 s~(-1))下的动态力学性能测试试验,获得材料在不同温度和应变率耦合作用下的应力-应变曲线,从中探讨温度和应变率对纯铁塑性流动应力的影响机制.研究表明,纯铁具有明显的热软化效应、应变率强化效应和应变强化效应,流变应力随温度的降低和应变率的增加而提高;利用所测的应力-应变曲线拟合的Johnson-Cook本构模型可以较好地预测纯铁的塑性流变应力.
이용대유가열장치화동보조장계통적분리식Hopkinson압간장치대순철진행관온도범위(293～1 073 K)、고응변속솔 (2 000～8 500 s~(-1))하적동태역학성능측시시험,획득재료재불동온도화응변솔우합작용하적응력-응변곡선,종중탐토온도화응변솔대순철소성류동응력적영향궤제.연구표명,순철구유명현적열연화효응、응변솔강화효응화응변강화효응,류변응력수온도적강저화응변솔적증가이제고;이용소측적응력-응변곡선의합적Johnson-Cook본구모형가이교호지예측순철적소성류변응력.
The experiment of dynamic mechanical behaviors test of pure iron is carried out at wide temperatures range (293～1 073 K) and high strain rates (2 000～8 500 s~(-1)) with split Hopkinson pressure bar, which is installed with heating device and synchro assembly system. The stress-strain curves of material under temperature-strain rate coupling actions are obtained. The mechanism of effect of temperature and strain rate on the plastic flow stress of pure iron is discussed. The studies show that the pure iron has evident heat softening effect, strain rate strengthening effect and strain hardening effect, and flow stress increases with temperature decreasing and strain rate increasing. The Johnson-Cook constitutive model that is fitted by stress-strain curves obtained from experiments can provide satisfactory prediction of the plastic flow stress of pure iron.