Bainite transformation kinetics, microstructure, and mechanical properties were comparably investigated by X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy observation, and tensile and impact tests for two treatments: with and without quenching before isothermal bainite transformation at 300 °C. Both the incubation time and growth stage of bainite transformation are accelerated by the introduction of prior martensite, especially the former. In addition, the bainite microstructure around the prior martensite is refined and shows a similar orientation with the martensite due to the strain field caused by the existence of prior martensite. The finer bainite microstructure and prior martensite improve the strength and hardness of the high-carbon nano-bainitic steel. Although the presence of prior martensite and low misorientation relationship between the martensite and the adjacent bainite microstructure are prejudicial to impact toughness, the nanoscale bainite microstructure can inhibit the crack propagation and then improve the impact toughness of the high-carbon nano-bainitic steel.

通过X射线衍射，扫描电子显微镜，电子背散射衍射，透射电子显微镜观察以及两种处理的贝氏体相变动力学，微观结构和力学性能进行了比较研究：两种方法：在300℃等温贝氏体相变之前进行淬火和不进行淬火℃。引入先有马氏体，尤其是前者，可加快贝氏体转变的保温时间和生长阶段。另外，由于由先有马氏体的存在引起的应变场，使在先马氏体周围的贝氏体组织细化并显示出与马氏体相似的取向。精细的贝氏体组织和先有的马氏体提高了高碳纳米贝氏体钢的强度和硬度。