Distribution of Bi-MnS inclusions in newly solidified steels subjected to horizontal cooling. Issue 10 (27th July 2022)

• Record Type: Journal Article
• Authors: Xie, Jian-bo; Liu, Bei-bei; Zhai, Qi-jie; Fu, Jian-xun
• Is Part Of: Materials and manufacturing processes. Volume 37:Issue 10(2022)
• Page Start: 1156
• Page End: 1164
• Publication Date: 2022-07-27
• Subjects: 1215MS -- Bi -- MnS -- impurities -- dendrite -- cooling -- thermodynamics -- grain; Manufacturing processes -- Periodicals; Materials -- Periodicals; Manufactured Materials; 670.5
• DOI: 10.1080/10426914.2021.2001519
• Languages: English
• ISSNs: 1042-6914

Abstract

ABSTRACT: To further study the distribution and concentration of Bi particles in various cooling zones in newly solidified Bi content 1215 MS steels and to explore the relationship between cooling rate ( R ) and dendrite arm spacing, the horizontal solidification experiments were carried out by altering the R . Thermodynamics show liquid Bi was immiscible in Fe, which precipitated in the grain boundary and tended to co-exist with sulfides. Under moving rate ν = 0.2 mm/s, the average sizes of Bi particles and Bi-MnS inclusions in the chilled boundary, columnar grain and quenching grain zones were 1.2 μm, 1.4 μm, and 1.5 μm, while under v = 0.4 mm/s, those were 1.3 μm, 1.6 μm, and 1.2 μm, respectively. The average dendrite arm spacing of the solidified steel decreased with increasing moving rate ( v ). At R = 0.367 and 0.690°C/s, the average equivalent diameter ( d ˉ e ) of the inclusions in the columnar grain zone was respectively 1.102 μm and 1.119 μm. Under v = 0.4 mm/s, the concentrations of Bi particles in 1200 ppm and 2800 ppm Bi solidified steels in the chilled boundary, solidification front and center of the quenching grain zone were 0.0267%, 0.0375%, 0.0443%, 0.0463%, 0.0659%, and 0.0832%, respectively.