Influence of Phosphorus Micro-Segregation on Ferrite Structure in Cast Strips of 0.1 mass% C Steel

Abstract

Cast strips of 0.1 mass% C steel with or without phosphorus addition have been characterized by electron back-scattering diffraction pattern (EBSP) measurements. Then the formation of globular ferrite structure was discussed. EBSP analysis combined with optical microscopy clearly showed that a globular grain was fitted to be an -ferrite grain. The EBSP analysis suggested that the retained-grain grew predominantly in the -grain and formed the globular -ferrite during cooling. The microtexture in the globular ferrite structure depended highly on the solidification structure. It is important to scatter the primary dendrite growth direction into neighboring areas to develop fine prior-and structures for the cast strip of high-phosphorus steel.

Effect of Nano-Scale Copper Sulfide Particles on the Yield Strength and Work Hardening Ability in Strip Casting Low Carbon Steel

“…In the previous works, the acicular ferrite was attributed to the large initial austenite grain size and the high cooling rate of the phase transformation. 1) In the present AC strip, the polygonal ferrite can be attributed to the Yoshida 11) and Umezawa 12) for the high phosphorus containing steel. The irregular and acicular ferrites are converted into a more regular polygonal structure through homogenization annealing, as shown in Fig.…”

Nucleation of Acicular Ferrite on Sulfide Inclusion during Rapid Solidification of Low Carbon Steel

“…Umezawa 32) and Yoshida 33) have also reported the similar effect of phosphorus on the alpha ferrite formation in ascast strip casting and conventional continuously casting steel. The sites rich in phosphorus are observed to be better place for alpha ferrite formation due to the effect of phosphorus on the local transformation temperature.…”

"In-situ" Observation of the .DELTA./.GAMMA. Phase Transformation on the Surface of Low Carbon Steel Containing Phosphorus at Various Cooling Rates

“…Phosphorus, which is usually considered to be an impurity in steel, has been reported to have great effects on phase transformation and to refine the prior-austenite grain size during the solidification process. [4][5][6] Phosphorus also causes some effects on sulfide precipitation in steel, 7) such as promoting the sulfide to precipitate at a smaller size.…”