钢中液态夹杂物聚并行为的数学物理模拟

基于相似原理，采用水模拟钢液，用有机试剂模拟钢液中液态非金属夹杂物，同时采用数值仿真方法共同研究了夹杂物种类、两相间界面张力及黏度对于液滴聚并过程的影响规律.结果表明，夹杂物液滴间的聚合趋势与其自身的物理性质有紧密联系，其中液滴相与连续相之间的界面张力会促进其相互聚并，而液滴相的黏度则正相反，在液滴聚并过程中起抑制作用.因此，通过改变液态夹杂物与高温钢液之间的界面参数以及黏度参数，有望达到聚合或分散的控制目标，进而实现夹杂物尺寸的灵活控制. 

Physical and numerical simulation of the coalescence of liquid inclusion particles in molten steel

In steelmaking process, nonmetallic inclusions are often considered to be detrimental to the mechanical properties and product quality of steel as they influence the microstructure of the steel matrix to a large extent, and thus, much industrial efforts are being made to promote inclusion removal by upward flotation. From this point of view, inclusions with large size are favorable; however, quality problems or mechanical defects are more likely to happen if some of them remain in the steel. In addition, fine nonmetallic inclusions can be utilized as nucleation sites of acicular ferrite during phase transformation to improve the steel strength by promoting the formation of a fine-grained structure; this procedure is known as oxide metallurgy. In both cases, the key issue is to control the size of inclusion particles. The main factor affecting inclusion size is the collision, agglomeration, and coalescence behavior of inclusions in the molten steel. Interfacial characteristics between inclusions and steel melts are known to have a significant influence on this coalescence behavior. To analyze this influence mechanism in depth, physical and numerical simulation methods were applied to investigate the effects of inclusion type, interfacial tension, and viscosity on droplet coalescence. Based on the similarity principle, water and organic reagents were chosen to simulate molten steel and liquid nonmetallic inclusions, respectively, in the physical modeling part. The results indicate that the coalescence tendency of inclusion droplets is closely related to the physical properties of the droplets. The interfacial tension between the droplet phase and the continuous phase promotes the mutual aggregation of droplets, while the viscosity of droplets plays an inhibitory role during the aggregation process. Therefore, it is feasible to achieve aggregation or dispersion of inclusions in liquid steel by changing interfacial or viscosity parameters, thereby realizing flexible control of the inclusions particle size.