ABSTRACT

The hot compression of A-100 steel at 850–1150°C and strain rate of 0.01–10 s⁻¹ was tested on a Gleeble-3800 thermal simulation machine to determine the corresponding true stress–strain curve. Based on theoretical calculation, the dislocation density factor was introduced into the Avrami equation and thereby a dynamic recovery physical constitutive relational model based on dislocation density theory was established. Then the hot deformation behaviour of A-100 steel was predicted (correlation coefficient R = 0.9964 with an average absolute relative error AARE = 4.0923%). The structures after hot compression were observed by electron backscattered diffraction and found to be lath-shaped martensite and austenite. With an increase of temperature and deceleration of strain rate, the proportions of large-angle boundaries and substructures increased and the softening mechanism became dominated by dynamic recovery.

摘要

在 Gleeble-3800 热模拟机上测试了 A-100 钢在 850–1150°C 和 0.01–10 s ^-1的应变速率下的热压缩，以确定相应的真实应力-应变曲线。在理论计算的基础上，将位错密度因子引入Avrami方程，建立了基于位错密度理论的动态恢复物理本构关系模型。然后预测了A-100钢的热变形行为（相关系数R = 0.9964，平均绝对相对误差 AARE = 4.0923%）。通过电子背散射衍射观察热压后的组织，发现为板条状马氏体和奥氏体。随着温度的升高和应变速率的减慢，大角边界和亚结构的比例增加，软化机制以动态恢复为主。