Effect of Boron on the Formation of the Naturally Deposited Film and Its Corresponding Interfacial Heat Transfer Behavior in Strip Casting of Boron-Containing Steel.

In this study, a droplet solidification technique was used to simulate the process of sub-rapid solidification and film deposition phenomenon in strip casting of boron-containing steel, and studied the effect of boron on the formation of the naturally deposited film and its corresponding interfacial heat transfer behavior. The results indicated that boron modified the surface tension of molten steel, thus increasing the interfacial wettability between the molten steel and substrate surface with the final contact angle decreasing from 102 to 89 deg, and improving the related heat transfer with maximum heat flux increasing from 6.23 to 9.11 MW/m². The deposited film was mainly composed of elements O, Fe, Si, Mn, B, and Cr. The increasing boron content made the deposited film particles melt faster and fuse more easily. Furthermore, the deposited films of the experiments with high boron content were thicker under the same deposition times; meanwhile, with the increase of boron content, the surface roughness of the deposited film increased gradually. In addition, the interfacial heat transfer behavior was mainly related to interfacial wettability and deposited film. Also, the deposited film composed of uniformly distributed small particles was better than tiny floccule or large clusters, and the relatively good film thickness was about 3.3–4.0 μm [ABSTRACT FROM AUTHOR]