316LN奥氏体不锈钢的高温流变行为与本构模型

利用Gleeble-3500热模拟试验机对锻造态316LN不锈钢进行了等温热压缩试验,研究了应变速率为0.001～1 s^-1、变形温度为1223～1523 K、压缩变形量为65%条件下材料的高温流变行为,建立了流变应力本构模型,并将其应用于Deform-3D软件平台,通过导入新材料数据,考虑界面摩擦等尺寸仿真了热模拟试验结果。结果表明:相同应变速率下,随着变形温度升高,316LN奥氏体不锈钢的压缩应力逐渐减小;相同变形温度下,随着应变速率增加,材料的压缩应力逐渐增大;且在真应力-真应变曲线中,随应变量增大,压应力在后期逐渐达到一个稳定值;考虑界面摩擦因数,并利用Arrhenius本构模型进行变形模拟仿真说明了本构方程和仿真模型的有效性和可靠性,可为316LN不锈钢材料的工程应用提供研究基础和理论依据。

High temperature rheological behavior and constitutive model of 316 LN austenitic stainless steel

Isothermal compression test was carried out by Gleeble-3500 thermal simulation testing machine with strain rate of 0.001-1 s^-1, deformation temperature of 1223-1523 K and compression deformation of 65% to study the high temperature rheological behavior of forged 316LN stainless steel. The rheological stress constitutive model was established and applied to Deform-3D software platform. The thermal simulation test results were simulated in equal size by importing new material data and considering interface friction. The results show that the compressive stress of 316LN austenitic stainless steel decreases with the increase of deformation temperature at the same strain rate. At the same deformation temperature, the compressive stress increases with the increase of strain rate. In the true stress-true strain curves, the compressive stress gradually reaches a stable value with the increase of strain. Considering the interface friction coefficient, the deformation simulation is carried out by using Arrhenius constitutive model, which shows the effectiveness and reliability of the constitutive equation and simulation model, and can provide research basis and theoretical basis for the engineering application of 316LN stainless steel.