论文部分内容阅读
利用Gleeble1500热模拟试验机在温度范围600~900℃、应变速率范围10-2~10 s-1等对HC1150/1400MS马氏体钢试件进行等温拉伸试验,进而构建了马氏体钢热加工过程的数值模拟需要的高温本构模型,用以根据应变、应变速率及变形温度预测流动应力。试验得到该材料奥氏体组织在不同温度及应变速率下的真应力、真应变曲线,显示材料的流动应力随变形温度的降低和应变速率的提高而增大,随变形温度的升高和应变速率的降低而减小。选用修正的Arrhenius双曲正弦模型对其高温力学行为进行描述,采用四次多项式拟合获得Arrhenius本构方程中参数α,β,n1,n,ln A,Q与应变的对应关系,最终确定包含变形温度及应变速率的流变应力计算方程。采用拟合度表示计算应力与实测应力的相关性,拟合度结果表明该本构模型对HC1150/1400MS马氏体钢高温流动应力的预测较准确。
The isothermal tensile test of HC1150 / 1400MS martensitic steel was carried out by using Gleeble1500 thermal simulator in the temperature range of 600 ~ 900 ℃ and the strain rate range of 10-2 ~ 10 s-1. The numerical simulation of the process requires a high-temperature constitutive model to predict the flow stress based on strain, strain rate and deformation temperature. The true stress and strain curves of the austenitic structure at different temperatures and strain rates were obtained by experiments. The results show that the flow stress of the material increases with the decreasing of the deformation temperature and the increase of the strain rate. With the increase of the deformation temperature and the strain The rate of decrease decreases. The modified Arrhenius hyperbolic sine model is used to describe its high temperature mechanical behavior. The quadratic polynomial fitting is used to obtain the corresponding relationship between the parameters α, β, n1, n, ln A, Q and strain in the Arrhenius constitutive equation. Finally, Deformation temperature and strain rate flow stress calculation equation. The fitting degree indicates the correlation between the calculated stress and the measured stress. The fitting degree results show that the constitutive model predicts the high temperature flow stress of HC1150 / 1400MS martensitic steel more accurately.