Original Article

Effect of Ce on the transformation of inclusions in the production process of duplex stainless steel F53

School of Metallurgy Engineering, Anhui University of Technology, Ma’anshan 243002, PR China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 4 March 2025
Accepted: 2 August 2025

Abstract

Inclusions significantly impact the metallurgical quality of stainless steel. Duplex stainless steel F53, produced by a domestic special steel enterprise, was found to exhibit surface cracks, severely compromising its mechanical properties. Laboratory microscopic analysis revealed that these defects are primarily caused by inclusions. To investigate the transformation of inclusions during production and the effect of the rare earth element cerium, this study analyzes the inclusion transformation mechanisms throughout the entire production process of duplex stainless steel. Samples from various stages were examined using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and ASPEX. The results show that, at the end of the AOD process, the inclusions in the molten steel primarily consist of MnS-MgO-Al₂O₃ composites. During the early LF stage, the inclusions are mainly MnS-MgO-CaO composites. After adding aluminum, the inclusions revert to MnS-MgO-Al₂O₃ composites, which remain throughout the LF process. Upon adding cerium, thermodynamic analysis using the FactSage 7.3 software reveals a significant reduction in sulfur content and a noticeable decrease in inclusion size. The main inclusions transform from MnS-MgO-Al₂O₃ to rare earth Ce₂O₃ and Ce₂O₂S inclusions, demonstrating effective modification. The precipitation sequence of rare earth inclusions is Ce₂O₃ first, followed by Ce₂O₂S, with Ce₂O₃-Ce₂O₂S composite inclusions forming simultaneously.