低锰铝系Fe-Mn-Al-C低密度钢的高温热塑性研究

High temperature thermoplasticity of Fe-Mn-Al-C low-density steel with low Al and Mn contents

本文基于工业化应用角度设计了一种Al、Mn含量较低的低密度钢,采用Gleeble 3500热模拟试验机对其高温热塑性进行研究,并采用金相显微镜、体视显微镜及扫描电镜对拉断后钢样的微观组织和断口形貌进行表征。结果表明,实验钢种的热塑性曲线在760~820℃出现了塑性低谷区,断面收缩率均小于80%,790℃拉伸时钢样的断面收缩率达到极小值,仅为54.45%,故实际生产中,实验钢种应避免在该温度范围进行连铸压下或热轧。在850~1200℃温度范围,实验钢种的热塑性能较好,断面收缩率均大于86%。另外,实验钢种的抗拉强度随着热拉伸温度的上升而下降,760℃时其抗拉强度最大为175 MPa。

In this paper,a low-density steel with low Al and Mn contents was designed for industrial application.The high-temperature thermoplasticity of the steel was tested on the Gleeble-3500 thermal simulator,and the microstructure and fracture morphology were characterized by optical microscope,stereomicroscope and scanning electron microscope.The results show that the thermoplastic curve of the steel shows a plastic groove between 760℃and 820℃with the area reduction rate less than 80%,and the area reduction rate of the steel reaches a minimum value of 55.45%at 790℃.Therefore,in actual industrial production,the continuous casting temperature and hot rolling temperature should not be in this temperature range.In the temperature range of 850~1200℃,the steel shows better thermoplastic performance,and the area reduction rates all exceed 86%.In addition,the tensile strength of the steel decreases with the increase of hot tensile temperature,and the maximum tensile strength is obtained at 760℃,which is 175 MPa.