CHEN Shu-ying
,
YUE Xu-dong
,
JIN Guang-can
,
LI Qing-chun
,
CHANG Guo-wei
钢铁研究学报(英文版)
The behavior of inclusions in the process of δ-phase growth during the solidification of Fe-015C-08Mn steel was in-situ observed using a high-temperature confocal scanning laser microscope (HTCSLM). The results show that inclusions arrive the S/L (solid/liquid) interface by way of direct impact or gradual drift, when the cell spacing is approximately equal to 177 μm during the growth of cellular δ-phase. The inclusions easily stay at the positions of trailing vortex formed by the circumferential motion of molten steel around δ-phase. Some inclusions reaching the S/L interface are captured by the solid-phase. Some of them move along the normal direction of the S/L interface because of pushing of solid-phase, and the others get away from the S/L interface after being pushed for a distance. The faster the growth rates of the solid-phase are, the easier the inclusions are captured by the S/L interface. The slower the growth rates of the solid-phase are, the easier the inclusions move with the S/L interface.
关键词:
inclusion
,
in-situ observation
,
carbon steel
,
solidification process
,
behavior
CHANG Guo-wei
,
CHEN Shu-ying
,
LI Qing-chun
,
YUE Xu-dong
,
JIN Guang-can
钢铁研究学报(英文版)
Abstract： Growth process of δ-phase was studied during the solidification of carbon steel. Through analyzing the solute diffusion around cylindrical crystals in the melt, the mathematic representation of lateral growth rate of cylindrical crystals was confirmed; the calculation and analysis of lateral growth rate were carried out. In order to validate the theoretical calculation and analysis, the growth process of δ-phase during the solidification was in-situ observed using a confocal scaning laser microscope (CSLM) and the growth rates were measured through CSLM images. The results show that lateral growth rates of δ-phase in the carbon steel first rapidly decrease with the increase of the radius of the cylindrical crystal, and then slowly fall down or maintain invariable. The radius of δ-phase is the primary factor to affect the growth rate. The higher the temperature gradient is, the bigger the growth rate is. However, the effect of the temperature gradient is feeble. Good correlation is obtained between theoretical analysis and experiment results in absolute values of lateral growth rate and change rule.
关键词:
Key words: cell growth
,
solidification process
,
carbon steel
,
in-situ observation
