Interaction between Phosphorus Micro-Segregation and Sulfide Precipitation in Rapidly Solidified Steel—Utilization of Impurity Elements in Scrap Steel

Abstract

Copper is one of the main residual elements in steel, especially in recycled scrap steel. Sulfur and phosphorus are two of the main impurities in steel, and it may result in a large emission of slag and CO 2 to remove them from steel. Utilization of these elements has been an important and difficult matter for metallurgist. In the present paper, the as-cast steels containing different concentrations of copper, sulfur and phosphorus are prepared by strip casting process or laboratory rapid solidification process. The effect of phosphorus addition on sulfide precipitation is investigated and discussed with respect to the morphology, size, and composition of sulfide. Both experimental results and mathematical calculation showed that the addition of phosphorus retards the sulfide precipitation at high temperature, promotes more copper bearings and smaller sulfides precipitation at low temperature. On the other hand, sulfide precipitates are shown to reduce the micro-segregation degree of phosphorus in steel, which may be because some phosphorus dissolves in sulfide and sulfide particles provide more interfaces for phosphorus to distribute.

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

“…In a recent paper by present authors, 34) the interaction between the microsegragation of phosphorus and sulfide precipitation has been investigated in copper bearing low carbon steel. Phosphorus could retard the sulfide precipitation at high temperature, promotes more copper bearings and smaller sulfides precipitation at low temperature.…”

Formation Behavior of M₂C and M₆C Eutectic Carbides in M42 High-Speed Steel

“…It has been widely reported that surface-active elements can affect the segregation of alloying elements. 9,25,[33][34][35][36][37] Regarding high-speed steels, Jiao et al 9) reported that Mg increases the segregation of C in the residual melt in M42 steel but decreases segregation of Mo. Yin et al 25) and Qu et al 36) found that RE decreases the segregation of C, Mo and V in the residual melt in M2.…”

Effect of Direct Powder Additions on the Solidification Structure and Microsegregation of 42CrMo4 Steel

“…Sulfur removal is well known to decrease the solidification range as well as changing the surface energies. [42][43][44] The properties of the liquid would then be totally different and could explain why the microsegregation intensity is lower for inoculated samples where the grain size is not affected. Further investigations need to be done to verify that hypothesis.…”