40CrNi2MoE钢挤压工艺的动态再结晶动力学模型分析

Dynamic recrystallization kinetics model analysis of 40CrNi2MoE steel extrusion process

为明确40CrNi2MoE钢在挤压工艺下的动态再结晶状态和高温流变特征,研究对该材料实施高温挤压处理,并通过台式场发射电镜和电液伺服动态疲劳试验机对其应变状况和结晶状态进行观测。在获得40CrNi2MoE钢应力-应变曲线的基础上,基于Arrhenius函数建立该材料的热变形方程,发现其热变形激活能Q为343.887 kJ/mol,当应变速率在0.1~10 s^(-1)之间且温度达到1 000℃以上时,才能够实现完全动态再结晶。40CrNi2MoE钢的峰值应变:ε_(p)与其Z参数之间的关系为:ε_(p)=0.028lnZ-0.35。以上数据对于40CrNi2MoE钢在加工过程中的组织晶粒细化具有一定的借鉴意义。

In order to clarify the dynamic recrystallization state and high-temperature rheological characteristics of 40CrNi2MoE steel under the extrusion process,the high-temperature extrusion treatment of the material was studied and the strain and crystallization state were observed by benchtop field emission electron microscope and electro-hydraulic servo-dynamic fatigue testing machine.On the basis of obtaining the stress-strain curve of 40CrNi2MoE steel,the thermal deformation equation of the material is established based on the Arrhenius function,and it is found that the activation energy Q of thermal deformation is 343.887 kJ/mol,and the complete dynamic recrystallization can be achieved when the strain rate is between 0.1~10 s^(-1) and the temperature reaches more than 1000℃.The relationship between the peak strainε_(p) and its Z parameter of 40CrNi2MoE steel isε_(p)=0.028 ln Z-0.35,and it is difficult for the material to undergo dynamic recrystallization under the condition of large Z parameters.The above data have certain reference significance for the micrograin refinement of 40CrNi2MoE steel in the processing process.