Effect of Cerium on the Cleanliness and Properties of an Al‐Killed Low‐Sulfur Steel

Abstract

Effects of the cerium content on inclusions, microstructure, and performance of an Al‐killed low‐sulfur steel are studied. As the cerium content in the steel increases from 0 to 190 ppm, the evolution path of the inclusion composition is Al2O3→CeAlO3→Ce2O2S + Ce2O3, and the inclusion size first decreases and then increases. When the cerium content is 76 ppm, the inclusion size reaches the minimum value. The addition of the ferrocerium is beneficial to the grain refinement of the Al‐killed low‐sulfur steel due to the low disregistry between inclusions and the steel matrix. The grain size of the steel decreases first, and it changes little after the cerium content reaching 76 ppm. The grain refinement is beneficial to increase steel properties. However, excessive inclusions in steel with a high cerium content reduce the tensile strength and the plasticity of the Al‐killed low‐sulfur steel.