低合金钢FQK400高温拉伸的流变特性

Flow Behavior of Low Alloy Steel FQK400 During Stretching at High-temperature

测定了FQK400低合金钢在不同温度、不同速率下的应力-应变曲线,分析了高温应力流变规律,对抗拉强度、峰值应变和拉伸温度、拉伸速率之间的关系进行了数学回归。结果表明,FQK400钢发生动态再结晶的条件是温度在850℃以上、拉伸速率在10×10-3s-1以下。钢的抗拉强度随拉伸温度的提高呈抛物线降低;峰值应变随温度的升高呈抛物线状先降后升,谷值温度为700℃,最大应变随温度的升高先升高后降低,700℃时最高。抗拉强度、峰值应变也随拉伸速率的提高呈抛物线关系上升,而最大应变则随拉伸速率的提高而降低。800℃下、拉伸速率为0.02s-1以下时为韧性断裂,拉伸速率为0.1s-1以上时为脆性断裂。

The stress-strain curves of FQK400 at different temperature and different deformation rate was determined, the flow stress law was analyzed. The relations between tensile strength, peak strain and tensile temperature, tensile rate were regressed. The results show that the condition for dynamic recrystallization of FQK400 is temperature over 850 ℃ and deformation rate below 10×10-3 s-1. Tensile strength reduces with the increase of temperature, peak strain reduces first and then increases with the increase o...