为系统研究含Nb高强IF钢UF340热轧精轧过程中的再结晶行为,在首钢迁钢2160热轧产线进行了轧卡工艺试验,并通过场发射扫描电子显微镜对各机架轧制后的材料组织进行表征分析。研究发现,在前两道次精轧过程中,UF340均可独立完成一轮再结晶形核长大,机架间微观组织呈完全再结晶状态;由于Nb的固溶拖拽作用,UF340再结晶被推迟,热轧F3~F5道次仅完成部分再结晶;在后部机架累积轧制变形作用下,UF340经F6道次轧制后再结晶较充分,精轧出口组织由较均匀的等轴晶粒组成,主要织构为{001}<110>旋转立方织构。结合UF340热轧过程,对其进行再结晶热力学计算,计算结果与试验结果一致性较好。依据该计算结果调整精轧各机架负荷分配,使UF340热轧过程中再结晶更为充分,使其边部组织均匀性得到明显改善。
Abstract
In order to systematically study the recrystallization behavior of Nb-containing high strength IF steel (UF340) during hot rolling and finishing rolling, the rolling process test was conducted in hot rolling line of Shougang Qiangang 2160. The microstructure of rolled material in each frame was characterized by field emission scanning electron microscope. It was found that the recrystallization nucleation and growth in UF340 were finished independently in the first two finishing rolling processes, and the microstructure between the frames was completely recrystallized. Due to the solid solution drag effect of Nb, the recrystallization in UF340 was retarded and partial recrystallization occurred at hot rolling F3-F5. Under cumulative rolling deformation of the final frame, the recrystallization of UF340 was sufficient after F6 rolling, and the microstructure after finish rolling was composed of the uniform equiaxed grains. The main texture was rotated cube texture ({001}<110>). Thermodynamic calculation of recrystallization in hot rolling of UF340 was conducted, and the calculated results were in good agreement with the experimental data. According to the calculation results, the load distribution of each frame in finishing rolling was adjusted to make the recrystallization of UF340 more adequate in hot rolling process, and the microstructure uniformity of edge was obviously improved.
关键词
UF340 /
含Nb高强IF钢 /
热轧 /
微观组织 /
再结晶 /
电子背散射衍射(EBSD)
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Key words
UF340 /
Nb-containing high strength IF steel /
hot rolling /
microstructure /
recrystallization /
electron back scattering diffraction (EBSD)
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参考文献
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脚注
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基金
中信铌钢发展奖励基金(M1922-2023,2023FWNB-30120)
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