基于Thermecmastor热模拟技术的Q235低碳钢平面应变研究  

Study on plain strain compression of low carbon steel based on Thermecmastor thermal simulation technology

作　　者：史杰杰 王昌[1] 王哲[1] 李继康[1] 胡蝶 SHI Jiejie;WANG Chang;WANG Zhe;LI Jikang;HU Die(Central Laboratory,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China;Institute for Science and Technology Information and Strategy,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司中心实验室,北京100081 [2]钢铁研究总院有限公司科技信息与战略研究所,北京100081

出　　处：《钢铁》2024年第7期150-158,共9页Iron and Steel

摘　　要：试样的几何尺寸会影响试样在平面应变压缩时的局部形变量,局部形变量的改变影响试样冷却过程中的微观组织,进而影响力学性能。在模拟轧制时,平面应变技术具有更好的相似性,为了更合理和准确地研究基于热模拟机的大试样平面应变技术,实现材料从工艺到力学性能的研究,利用Thermecmaster热模拟机对尺寸为30 mm×30 mm×140 mm的Q235低碳钢进行了平面应变压缩试验。基于Thermo-Calc软件计算得到的Q235低碳钢奥氏体相变温度,制定了低碳钢的热模拟工艺,通过分析平面应变试样的变形区、过渡区和未变形区的微观组织演变规律,确定了试样在该工艺下的组织相对均匀区域。在此基础上,加工出合理尺寸的拉伸和冲击韧性试样并进行测定与对比分析,同时利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和电子背散射衍射(EBSD)技术和透射电子显微镜(TEM)对平面应变前后的微观组织进行了对比与分析。与原始试样相比,平面应变试样力学性能的提高主要是由于铁素体晶粒的细化以及分布更加均匀细小的珠光体。基于Thermecmastor热模拟试验机的大试样平面应变技术实现了Q235低碳钢的工艺→微观组织→力学性能的研发模式,为研究钢铁等金属材料在同一试样的微观组织与力学性能提供热模拟方法。同时通过对比分析平面应变前后试样的微观组织与力学性能,探索出优化商用Q235低碳钢力学性能的热模拟工艺,为工业优化商业Q235低碳钢提供理论指导与数据支撑。The local strain changed when the specimen geometry was different during plain strain compression.The microstructure and mechanical properties of specimen changed corresponding to different local strain after cooling.The process of plane strain compression is particular similar to rolling.To study the plane strain compression technology of large sample more reasonably and accurately based on thermal simulation machine and realize the material research from process to mechanical properties,the plane strain compression experiment of Q235 low carbon steel with dimension of 30 mm×30 mm×140 mm was carried out by Thermecmastor.Based on the austenite transformation temperature calculated by Thermo-Calc software,the thermal simulation process was confirmed.Combined with the metallographic microscope,the microstructure evolution law of the deformation zone,transition zone and undeformed zone of the plane strain sample was analyzed and the microstructure of relative uniform area was determined.Based on the determined relative uniform area,the reasonable dimensions of tensile and impact specimens were processed and its mechanical property were charactered and compared with original specimens.The microstructure before and after plain strain compression were charactered by X-ray diffraction(XRD),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM).The improvement of the mechanical properties of the plane strain sample was mainly due to the refinement of ferrite grains and the smaller size and more uniform distribution of pearlite clusters.Based on the plane strain compression technology of Thermecmastor,the research mode of process→microstructure→mechanical properties of low carbon steel was realized,which provided a thermal simulation method for studying the microstructure and mechanical properties of metal materials such as steel in the same specimen.At the same time,by comparing and analyzing the microstructure and mechanical properties of specimens before

关 键 词：平面应变 Thermecmastor Q235低碳钢 微观组织 力学性能 晶粒细化 

分 类 号：TG142.31[一般工业技术—材料科学与工程]