材料动态性能是当前力学性能研究领域中最为活跃的方向之一，研究材料的动态力学性能在力学研究中有其重要意义，对军用和民用新材料的设计具有实际应用意义和科学价值。
在合金钢中，如果铁素体中含有0.08%以上的氮元素或者奥氏体中含有0.4%以上的氮元素，则这种钢就称为高氮合金钢（HNS）。钢中的氮元素与其他元素（Mn、Cr、V、Nb、Ti等）交互作用，赋予了高氮钢许多优异的性能：如强度高、塑性和韧性好、蠕变抗力大、耐腐蚀性好等，高氮钢的这些性能使它成为穿甲弹和装甲的理想材料之一。因此，对高氮钢的动态性能和动态本构关系研究将具有深远的科学意义。
本论文采用实验测试与理论分析、数值模拟相结合的研究方法，对两种工艺流程制备的高氮合金钢材料进行动态压缩实验，获得了它们的动态应力-应变关系，为研究其动态性能和动态本构关系提供依据。
利用分离式Hopkinson压杆(SHPB)实验技术对两种不同工艺流程——空冷和水冷高氮钢材料进行动态压缩实验，得到大量精确的数据，得出这两种材料在不同应变率情况下的应力-应变曲线和动态压缩屈服强度。结果表明：两种工艺流程的高氮钢材料动态应力-应变关系具有明显的率相关性，而动态压缩屈服强度应变率效应较弱，但应变硬化的应变率效应明显。
采用Johnson-Cook本构模型来描述这两种工艺制备的高氮钢材料的动态力学行为，通过对实验结果的拟合，确定了J-C本构模型中的参数，得到的Johnson-Cook本构关系曲线与动态压缩实验所得的应力-应变关系曲线比较吻合，拟合过程在Origin7.0软件上进行。
运用大型通用有限元程序ANSYS/LS-DANY对两种材料的动态压缩试验进行有限元模拟，模拟过程中试件的J-C本构模型参数采用实验数据拟合所得，最后，得到了试件变形情况，并根据模拟数据应用Hopkinson压杆计算程序得出了应力-应变关系，发现模拟结果得到的应力-应变关系曲线与实验曲线比较一致。
对比了高氮钢材料和603装甲钢的弹道极限速度（穿透概率为50%时模拟破片或特定弹丸的平均着靶速度），并建立了高速弹丸侵彻高氮钢靶板和603装甲钢靶板的有限元模型，分别对高氮钢材料和目前国内普遍使用的603装甲钢进行了抗侵彻能力模拟，模拟过程中弹丸和靶板的本构模型均使用Johnson-Cook本构模型，得到高氮钢靶板的弹道极限速度和抗侵彻能力优于603装甲钢的结论。

The dynamical performance of material is one of the most active direction in the mechanical performances researches, and researching the dynamical performances of materials has important means in the mechanical researches. For military and civilian design of new materials, these researches have practical applications of significance and scientific values.
The alloy steels are named High Nitrogen Steels (HNS) if the nitrogen element percent in the ferrites is above 0.08% or the nitrogen percent is more than 0.4% in the austenite. The nitrogen element can endow the High Nitrogen alloy Steel many excellent performances by the interactive action with the other elements (Mn, Cr, V, Nb, Ti etc): such as high intensity, good toughness and plasticity, large creep resisting force, good corrosion resistance and so on. These performances make High Nitrogen Steel as a perfect armor and armor-piercing bullet material. Thus, researching the dynamical performances and the dynamical constitutive equations of High Nitrogen Steel will have profound scientific significance.
In this paper, practicing the dynamical compression experiments on the High Nitrogen Steel made by two different technology processes by using the method of experimental test associated with theoretical analysis and numerical simulation, and then we could get their dynamical stress-strain relationship. These achievements were basic to research the dynamical performances and dynamical constitutive law of High Nitrogen Steels.
Dynamical compression experiments to the High Nitrogen Steel made by two different technologies processes —air-cooling and water-cooling, have been done by the split Hopkinson pressure bar (SHPB) technique. During these experiments, we could get a lot of exact data, then obtained the stress-stain relation curves and the dynamical compress yield strengths in different strain-rates of the both specimens. The results showed that for High Nitrogen Steel made by two different technology processes, the dynamical stress-strain relations had obvious rate-relevance, and the strain-rate effect of dynamical compression yield strengths was weak, but the strain-rate effect of strain hardening was obvious.
Described the dynamical mechanical behaviors of the High Nitrogen Steel made by two different technology processes with the Johnson-Cook constitutive models, and determined the parameters in the Johnson-Cook constitutive models by fitting the experimental results. The fitted Johnson-Cook curves were well inosculated with the stress-strain curves obtained from the dynamical compression experiments on High Nitrogen Steel, and the fitting processes were finished by Origin 7.0 software.
In this paper, finite element simulations to the two kinds of High Nitrogen Steel materials had been done by using the large general-purpose finite element software: ANSYS/LS-DYNA. The parameters of Johnson-Cook constitutive model were obtained by fitting the experiment data. At the end of the finite element simulation, we got the deformation of the specimens, and also obtained the stress-strain relation curves of the specimens from treating the simulated data by the calculating procedure of the Hopkinson pressure bar. These curves of simulation results showed that they were well inosculated with the curves obtained by the dynamical compression experiments.
Compared the ballistic limit velocity (simulating the average-target velocity of the fragments or special bullet when the transmission probability was 50%) of the High Nitrogen Steel material with the ballistic limit velocity of the 603 armored steel, and also set up the finite elements models of high-speed projectile penetrating the High Nitrogen Steel target and 603 armored steel target, simulated the armor penetration abilities of the High Nitrogen Steel and 603 armored steel. 603 armored steel was widely used at current. Both of the constitutive models of bullet and target were Johnson-Cook constitutive models during the simulation process.The result showed that the ballistic limit velocity and the armor penetration ability of High Nitrogen Steel was better than that of the 603 armored steel.