双辊薄带微幅振动铸轧新技术基础研究

As one of the near-net technology, twin-roll strip casting process has received considerable interest world wide over the last decade. The process produces thin strips directly from the molten metal with less energy consumption and greater productivity, and it has been deemed as the next generation of steel production. However, given the fact that the casting parameters of traditional twin-roll strip casting process are in a very narrow range and difficult to control, which leads to the existence of segregation and internal cracks, it is hard to maintain the quality of the strip. Thus, the present project proposes a novel approach: in order to alter the solidification phenomena of liquid steel in the molten pool, we implement adjustable frequency and small amplitude vibration (micro-vibration) into the casting process, then study the relationship between casting speed, interfacial heat transfer on the roller surface and solidification phenomena in the mushy zone, and research the interaction between parameters of vibration and the solidification kissing curve in the mushy zone. Experiments research such as study on the effects of vibration parameters on the microstructure of the strip, influence of vibration parameters on the grain size and uniformity of the strip, optimization of casting parameters to prevent internal break out, can be carried out by improving structural parameters of existing pilot twin roll casting machine in our lab. Our project can provide further theoretical insights and practical values into the process, so as to improve our technology level and promote the development of near-net process technology, thus, world-wide leading edge will be granted.

双辊薄带铸轧是近十多年来国内外努力发展的短流程技术，具有显著的高效节能降耗特征，已成为未来钢铁工业发展的主导技术。由于传统双辊薄带铸轧凝固区域理想可控参量难于匹配，极易在带钢心部产生夹层偏析和内裂，铸轧产品质量难于稳定控制。为此，本项目提出采用振频可调的微幅振动（简称微振）铸轧技术改变熔池液态金属凝固过程，研究液固两相区凝固形态与铸速、辊间换热规律，研究振动频率、微幅效应对液固两相区金属凝固终了曲线的影响。通过改善实验室现有双辊薄带铸轧机结构参数，开展相关实验研究。分析微振参数对铸轧带坯组织性能的影响，研究微振铸轧对带材晶粒细化、晶粒均化的作用，提出防止心部夹层开裂最佳工艺参数。本项研究对提高我国自有双辊薄带铸轧技术水平和加速钢铁短流程工业技术进步具有重要理论意义和实际应用价值，研究成果处于国际领先地位。

双辊薄带铸轧是近十多年来国内外努力发展的短流程技术，具有显著的高效节能降耗特征，已成为未来钢铁工业发展的主导技术。由于传统双辊薄带铸轧凝固区域理想可控参量难于匹配，极易在带钢心部产生夹层偏析和内裂，铸轧产品质量难于稳定控制。为此，本项目提出采用振频可调的微幅振动（简称微振）铸轧技术改变熔池液态金属凝固过程，研究液固两相区凝固形态与铸速、辊间换热规律，研究振动频率、微幅效应对液固两相区金属凝固终了曲线的影响。通过改善实验室现有双辊薄带铸轧机结构参数，开展相关实验研究。分析微振参数对铸轧带坯组织性能的影响，研究微振铸轧对带材晶粒细化、晶粒均化的作用，提出防止心部夹层开裂最佳工艺参数。本项研究对提高我国自有双辊薄带铸轧技术水平和加速钢铁短流程工业技术进步具有重要理论意义和实际应用价值，研究成果处于国际领先地位。