Modification of Alumina Inclusions in SWRS82B Steel by Adding Rare Earth Cerium

Abstract

The aluminum oxide inclusions in SWRS82B steel seriously affect the drawing performance of the steel strand. In this study, the influence of different additions of cerium (within the range of 0–0.034%) on the composition, morphology, size, number, and distribution of alumina inclusions was studied by scanning electron microscope and energy spectrum analyzer. The evolution of the composition of inclusions with different cerium additions was calculated based on classical thermodynamics and Factsage software calculation. The thermodynamic calculated results were consistent with the experimental results. It indicates that the modification route of Al2O3 inclusions in SWRS82B steel by increased cerium additions is as follows: Al2O3 → Ce2S3 + CeAlO3 + Ce2O2S + Al2O3 → Ce2S3 + CeAlO3 + Ce2O2S/Ce2S3 + Ce2O2S → Ce2S3 + Ce2O2S. Besides, when the amount of cerium is in the range of 0.023% to 0.030%, CeAlO3 inclusions gradually disappear. The best characteristics of inclusions in this study were obtained in experimental samples with cerium addition of 0.023%, in which the minimum size of inclusions is in the range of 3.52–4.84 μm and mostly uniform distribution. Finally, the mechanism on the modification by cerium was discussed based on the composition evolution of inclusion during solidification with Factsage calculation and experimental results. The compositions of inclusions were also analyzed based on the inclusion evolution model.

Evaluation of different alloying concepts to trace non-metallic inclusions by adding rare earths on a laboratory scale

“…Referring to Wang et al [26], the addition of rare earths increases the number density of inclusions, and, aside from that, the NMIs get smaller and spherical. Similar tendencies are observed by Li et al [31] and Wang et al [32]. In both studies, the irregularly shaped inclusions become more globular, and at low Cerium addition, their sizes decrease.…”

Investigating the Origin of Non-Metallic Inclusions in Ti-Stabilized ULC Steels Using Different Tracing Techniques

“…In this method, NMIs are partially reduced due to the direct addition of rare earth elements (REEs) [17]. Several studies [18][19][20][21] have already managed to track the modification of deoxidation products, such as alumina NMIs, by adding La and Ce to the melt on industrial and laboratory scales. The benefit of this approach is the easy retrieval of REE-marked NMIs during automated scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS) analysis, since REEs appear brighter than the steel matrix in backscattered electron (BSE) images due to their higher atomic number [22].…”

Correlation Between Nonmetallic Inclusions and Localized Corrosion of a Low‐Nickel Stainless Steel with Cerium Treatment

“…In recent years, with the increasing demand for high-quality stainless steels, rare earth (RE) elements have attracted the attention of scholars due to their significant influence on the steel. [1][2][3][4][5][6][7][8] Inclusions in the steel, which have an important impact on the performance of the steel, [9][10][11][12] could be effectively modified by RE due to its strong affinity to oxygen and sulfur, [13][14][15][16][17][18] thus, influencing the property of the steel. Wang et al [19] found that an appropriate addition of RE reduced the susceptibility of pitting corrosion and improved the corrosion resistance of a duplex stainless steel.…”