两相区热轧对20钢组织和力学性能的影响

The Effect of Hot-rolling in Two-phase Zone on Microstructures and Mechanical Properties of 20 Steel

本文利用Gleeble-3500热模拟试验机对20钢（α＋γ）两相区内进行热压缩试验，获得不同变形条件下的真应力-真应变曲线，结果表明：当变形温度相同时，流变应力随着应变速率的增大而增大；当应变速率相同时，流变应力随着变形温度升高而减小，但在850℃时略有增大现象。采用光学显微镜（OM）和场发射扫描电镜（FG-SEM）技术分析了变形温度为750-850℃、应变速率为1s^-1时的20钢微观组织变化，得出结论：20钢在两相区轧制时，在750-820℃，温度是影响力学性能的主要因素；在820-850℃，（α←→γ）相变是影响力学性能的主要因素。

This paper do compression test in two-phase zone of 20 steel （α＋γ） by Gleeble-3500 thermal simulation testing machine, get the true strees-true strain curve under different deformation conditions. The results show when the deformation temperature is the same, the flow stress increases with the increase of the strain rate. When the strain rate is the same, the flow stress decreases with the increase of the deformation temperature.but a slight increase phenomenon at 850 ℃.The microstructure of 20 steel with the deformation temperature ranging of 750-850 ℃ and the strain rate ranging of 1 s^-1 was studied by the optical microscope （OM） and field emission scanning electron microscopy （FG-SEM）. We get that temperatures are the main factors affecting the mechanical propertie in the range of 750- 820 ℃ during hot-rolling in two-phase zone of 20 steel, The （α←→γ） phase transformation is the main factor affecting the mechanical properties in the range of 820-850 ℃