Nitronic 60奥氏体不锈钢热变形行为研究
Investigation on Hot Deformation Behavior of Nitronic60 Austenite Stainless Steel
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摘要: 在Gleeble-3800热模拟试验机上对Nitronic60奥氏体不锈钢进行高温等温压缩实验,研究该材料在变形温度为950—1 200℃、应变速率为0.01—10 s-1、真应变量0.9等条件下的热变形行为,并观察了变形后的显微组织。研究结果表明:在热压缩过程中,流变应力随变形温度的升高而降低,随应变速率的升高而增加;当变形速率较低时,材料在变形温度范围内均发生了动态再结晶。采用双曲正弦模型建立了相应的热变形本构关系,其热变形激活能为425.542 k J/mol,高温压缩变形时,Z参数和流变应力方程分别为Z=εexp (425.542/RT)=3.495×1015sinh(0.005 93σ)5.55,ε=3.495×1015sinh(0.005 93σ)5.55exp-525.524/(RT)。Abstract: The hot deformation behavior of Nitronic60 austenite stainless steel was studied by high temperature isothermal compression test of cylindrical specimens at 950—1 200 ℃ with the strain rate of 0.01—10 s-1 and true strain of 0.9 on a Gleeble-3800 simulated machine.The microstructure after hot deformation were analyzed.The results show that during the hot compression process the flow stress decrease with the increase of deformation temperature and decrease of strain rate.When the strain rate is low, the dynamic recrystallization of the steel occurs in the range of deformation temperature.The hot deformation constitutive relationship was established using the hyperbolic-sine mathematics model.Its activation energy is 425.542 kJ/mol, and the Zenner-Hollomon (Z) parameter and flow stress equation for compress deformation at high temperature is Z = εexp (425.542 /RT) = 3.495 × 1015sinh (0.005 93σ) 5.55, ε= 3.495 × 1015sinh (0.005 93σ) 5.55exp- 525.524/(RT) , respectively.