Evolution of interfacial heat transfer, contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents
1 School of Metallurgy and Environment, Central South University, Changsha 410083, Hunan, China 2 National Center for International Research of Clean Metallurgy, Central South University, Changsha 410083, Hunan, China 3 Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu, China
Evolution of interfacial heat transfer, contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents
1 School of Metallurgy and Environment, Central South University, Changsha 410083, Hunan, China 2 National Center for International Research of Clean Metallurgy, Central South University, Changsha 410083, Hunan, China 3 Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu, China
摘要 Typical Q235 low-carbon steel samples with different hydrogen contents (0.0004, 0.0008, and 0.0013 wt.%) were prepared by adjusting the environment humidity and moisture. The effects of hydrogen on interfacial heat transfer, contact behavior, and microstructure evolution were investigated using a novel droplet solidification technique. The results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%, the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m2, and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m2. Moreover, the final contact angle between the molten steel and substrate increases from 103.741° to 113.697°, and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in hydrogen. The surface roughness of the droplet bottom surface increases from 20.902 to 49.181 μm. In addition, the average grain size of the droplet increases from 14.778 to 33.548 μm with the increase in the hydrogen content. The interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process, which leads to the reduction in the interfacial heat transfer and the increase in the grain size.
Abstract：Typical Q235 low-carbon steel samples with different hydrogen contents (0.0004, 0.0008, and 0.0013 wt.%) were prepared by adjusting the environment humidity and moisture. The effects of hydrogen on interfacial heat transfer, contact behavior, and microstructure evolution were investigated using a novel droplet solidification technique. The results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%, the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m2, and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m2. Moreover, the final contact angle between the molten steel and substrate increases from 103.741° to 113.697°, and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in hydrogen. The surface roughness of the droplet bottom surface increases from 20.902 to 49.181 μm. In addition, the average grain size of the droplet increases from 14.778 to 33.548 μm with the increase in the hydrogen content. The interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process, which leads to the reduction in the interfacial heat transfer and the increase in the grain size.
Cheng Lu,Wan-lin Wang,Chen-yang Zhu, et al. Evolution of interfacial heat transfer, contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents[J]. Journal of Iron and Steel Research International, 2024, 31(1): 215-223.
2024, Vol. 31 
