基于摩擦修正的单真空300M超高强度钢本构模型

Constitutive model on single vacuum 300M ultra-high strength steel based on friction correction

为研究单真空300M超高强度钢高温流变行为及制定合理的热加工参数,采用Gleeble-3800热模拟实验机在应变速率为0.01~10 s^(-1)、温度为850~1200℃下进行热压缩实验,研究其流变应力与变形温度、应变速率和变形量等参数的关系,并考虑了在圆柱试样压缩变形过程中摩擦对流变应力的影响,建立了基于摩擦修正的Arrhenius本构模型。采用热压缩实验测量试样流变应力时,试样上、下端面与实验机压头之间的摩擦不可忽视,经摩擦修正后可获得更加精确的材料高温流变应力;材料的流变应力与变形温度呈负相关,与应变速率呈正相关;材料的峰值应力对变形温度和应变速率均具有较高的敏感性,但对应变速率的敏感指数更高。

To study the high temperature rheological behavior of single vacuum 300M ultra-high strength steel and formulate reasonable thermal processing parameters,the thermal compression tests were carried out under the conditions of strain rate of 0.001-10 s^(-1),and deformation temperature of 850-1200℃,and the relationship between rheological stress and deformation temperature,strain rate and deformation amount was studied.Then,considering the influence of friction on rheological stress during compression deformation process of cylindrical specimen,an Arrhenius constitutive model based on friction correction was established.The research results show that when the rheological stress of sample is measured by the thermal compression test,the friction between the upper and lower end surfaces of the sample and the indenter of the test machine cannot be ignored.After the experimental results are corrected by friction,the more accurate high-temperature rheological stress of materials is obtained.The material rheological stress is negatively correlated with the deformation temperature and positively correlated with the strain rate.In addition,the peak stress of the material has a high sensitivity to both the deformation temperature and the strain rate,but the sensitivity index to the strain rate is higher.