大变形冷轧Fe-6.5%(质量)Si高硅钢薄板组织性能的研究

Effect of Heat Treatment on Microstructure and Properties of Heavily Cold Rolled Fe-6.5 wt%Si Alloy Sheet

Fe-6.5%(质量)Si合金具有优异的软磁性能,有着良好的发展前景。但由于该合金中有序相的出现,人们难以用普通轧制的方法得到该合金的薄板。本文利用热轧,温轧,冷轧方法,结合相关的热处理手段,得到该合金0.05 mm薄板。通过在不同温度下热处理,利用光学显微镜,扫描电镜,X射线仪,拉伸机,显微硬度仪,研究该薄板组织结构和力学性能的变化。利用磁滞回线仪研究薄板热处理前后直流磁性能的变化。通过研究发现,0.05mm轧态薄板具有一定的塑性,断裂强度高达1.93 GPa。热处理使薄板硬度降低,塑性降低,特别是在650℃以上,材料发生了再结晶后,变化尤为明显。究其原因是有序相B2向DO3的转变及<001>面织构的消失。

Fe-6.5wt%Si alloy has excellent soft magnetic properties,but it is hard to be cold rolled due to appearance of ordered phases in this alloy.It′s reported that ultra thin sheet of 0.05 mm thick could be obtained by hot,warm,and cold rolling method,including heat treatment.The heavily cold rolled sheets were heat treated at different temperatures.By means of optical microscope,SEM,X-ray diffraction,tensile machine and micro-hardness indenter,the relationship between the microstructure and mechanical properties was investigated.By means of hysteresiscope,the ac magnetic property change before and after heat treatment was investigated.It is found that the heavily cold rolled sheet has certain ductility,and the ultimate tensile strength reaches to 1.93 GPa.Heat treatment softens the sheet but decreases the ductility,especially above 650 ℃ when recrystallization happens.The reason lies on the transition of B2 to DO3 and disappearance of 001 plane texture.