应变速率对建筑结构用钢高温热塑性的影响

Effect of Strain Rate on High Temperature Thermoplasticity of Structural Steels for Buildings

高性能建筑用钢可有效提升材料力学性能,研究中对材料的高温热塑性进行了分析,选择通过热模拟和显微观察方式研究低合金高性能建筑结构用钢在不同应变速率下的变化情况。研究结果表明:在10-3s-1低应变速率下,充足的变形时间导致铁素体析出量更多,从而出现了塑性低谷;在10s-1应变速率下,塑性低谷随即消失,在1 000℃~1 200℃范围内,断面收缩率随温度提高而逐渐降低,热塑性变形得到明显改善。

Low-alloy high-performance construction steel can effectively improve the mechanical properties of the material.In the study,the high-temperature thermoplasticity of the material was analysed,and it was chosen to study the changes of low-alloy high-performance construction steel at different strain rates by thermal simulation and microscopic observation.The results show that:at a low strain rate of 10-3s-1,the sufficient deformation time leads to more ferrite precipitation,which results in a plasticity trough;at a strain rate of 10s-1,the plasticity trough disappears immediately,and the thermoplastic deformation is significantly improved in the range of 1000~1200℃,as the section shrinkage gradually decreases with the increase of temperature.