Effect of Cerium Addition on Inclusion Evolution and Mechanical Performance of Wind Power Steel

This study investigates the effect of rare earth cerium (Ce) addition on oxide inclusion evolution and the mechanical properties of wind power steel through a combination of thermodynamic calculations, first‐principles analysis, and experimental validation. First‐principles calculations reveal that Ce‐containing oxides exhibit higher interfacial separation work with the Fe matrix, indicating stronger interfacial bonding and improved interfacial stability, which promotes the formation of stable spherical Ce‐bearing inclusions and reduces stress concentration around inclusions. Experimental studies were conducted on steels containing 0, 22 ppm, and 66 ppm Ce. Microstructural characterization shows that Ce addition refines the grain structure, modifies irregular inclusions into spherical or elliptical morphologies, and improves their size distribution. As a result, the low‐temperature impact toughness is significantly enhanced. The transverse impact energy at −40°C increases from 193 J in the Ce‐free steel to 291 J in the 66Ce steel, accompanied by the elimination of toughness anisotropy. These results demonstrate that Ce effectively regulates inclusion characteristics and interfacial bonding behavior, thereby improving the low‐temperature toughness of wind power steel. The present work provides mechanistic insight into rare‐earth inclusion modification and offers guidance for the alloy design of high‐performance wind power steels.