论文部分内容阅读
通过优化成分设计、热模拟试验及控轧控冷技术在试验轧机上得到了超细化的贝氏体组织,并采用金相显微镜和透射电子显微镜对超细组织的形貌及其亚结构进行了观察。结果表明:当非再结晶区压缩比达到8时,在厚度方向上原奥氏体晶界间距小于5μm,使得相变得到的贝氏体束尺寸显著减小,此时钢的抗拉强度达到1000 MPa、平均伸长率大于14%、-30℃冲击吸收能量达到120 J。透射电镜结果显示,此时单个贝氏体板条宽度小于200 nm,且在其内部存在高密度位错及纳米级胞状亚结构,而在位错上则分布着大量的尺寸小于10 nm的析出颗粒,其对位错产生强烈的钉扎作用,不但提高了钢的强度,而且也提高了胞状位错亚结构的稳定性,使得组织进一步细化,进而改善钢的综合力学性能。
Through the optimization of component design, thermal simulation and controlled rolling and controlled cooling technology, the ultrafine bainite structure was obtained on the experimental rolling mill. The microstructure and the substructure of the ultrafine structure were studied by metallographic microscope and transmission electron microscope Observed. The results show that when the compression ratio of non-recrystallization zone reaches 8, the spacing of the original austenite grain boundaries in the thickness direction is less than 5 μm, the size of the bainite beam obtained by phase transformation is significantly reduced, and the tensile strength of the steel reaches 1000 MPa, the average elongation is more than 14%, and the impact absorption energy at 30 ℃ reaches 120J. Transmission electron microscopy results showed that the width of a single bainite slab was less than 200 nm, and there were high-density dislocations and nanosized cellular sub-structures in its interior, while a large number of precipitates with sizes less than 10 nm were distributed on dislocations Particles, which have a strong pinning effect on dislocations, not only improve the strength of the steel, but also improve the stability of the dislocation dislocation structure, making the organization further refinement, thereby improving the overall mechanical properties of steel.