论文部分内容阅读
采用Gleeble-3500型热模拟试验机对高铁螺纹道钉钢TD16进行热压缩变形实验,探索该材料在不同温度和应变速率条件下的热塑性变形行为。研究温度与应变速率对真应力-真应变曲线的影响规律,结合显微组织分析,阐明真应力-真应变曲线发生变化的原因。结果表明,在低应变速率下,流变应力峰值较明显,具有明显的动态再结晶特征。在较高应变速率下,峰值应力不明显,流变应力曲线属于动态回复型,未发生动态再结晶。通过回归分析,建立高铁螺纹道钉钢TD16在实验条件范围内的峰值流变应力本构关系的数学模型。所建立的流变应力本构方程与实验值吻合较好,最大相对误差为7.03%,可以用该本构方程来预测高铁螺纹道钉钢TD16的高温流变行为。
The hot deformation test of high speed railway screw steel TD16 was carried out by Gleeble-3500 thermal simulation test machine to explore the thermoplastic deformation behavior of the material under different temperature and strain rate conditions. The influence of temperature and strain rate on true stress - true strain curve was studied. The reason of the change of true stress - true strain curve was clarified by combining microstructure analysis. The results show that at low strain rate, the peak value of flow stress is more obvious and has obvious dynamic recrystallization characteristics. At higher strain rates, the peak stress is not obvious, and the flow stress curve belongs to the dynamic recovery type, and no dynamic recrystallization occurs. Through regression analysis, the mathematical model of the peak flow stress constitutive relation of high-speed railway screw steel TD16 in the experimental condition was established. The established rheological stress constitutive equation is in good agreement with the experimental value, the maximum relative error is 7.03%. This constitutive equation can be used to predict the high temperature rheological behavior of high-speed railway screw steel TD16.