Roles of titanium-rich precipitates as inoculants during solidification in low carbon steel

Ming-lin Wang1,2),Guo-guang Cheng3),Sheng-tao Qiu1,2),Pei Zhao1),and Yong Gan1) 1) The State Key Laboratory for Advanced Steel Process and Products,Central Iron and Steel Research Institute,Beijing 100081,China 2) National Engineering and Research Center for Continuous Casting Technology,Central Iron and Steel Research Institute,Beijing 100081,China 3) Metallurgical and Ecological Engineering School,University of Science and Technology Beijing,Beijing 100083,China

摘 要：The effect of titanium on the as-cast structure and the growth form of titanium precipitates,and the effect of cooling rate on the size and distribution of titanium precipitates were studied.It is shown that Ti-rich precipitates acting as heterogeneous nucleation sites play an important role in refining the grain size and increasing the equiaxed grain ratio.Cooling rate has a great effect on the size and distribution of precipitates.The number of precipitates increases and the size decreases with the increase of cooling rate.Ti-rich particles acting as heterogeneous nucleation sites at the onset of solidification are observed in the experiment.This result suggests that TiN nucleated on Ti2O3 is an effective inoculant for δ-ferrite during solidification in low carbon steel.

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