The discovery of cerium oxide has brought many new discoveries to the steel industry. Cerium oxide has a strong affinity to sulfur as well as to oxygen. Adding a small amount of cerium to high-strength low-alloy and stainless steel can improve grain boundary stability and control the shape of sulfides during steel manufacturing. In 1984 Alcoa developed a high-temperature aluminum alloy to replace the heavier steel and titanium alloys used in the high-tech aerospace field, adding iron and cerium to improve its corrosion resistance at high temperatures, while the traditional aluminum alloy can only maintain its strength at 135 ℃ ~ 149 ℃.

The soft nonmetallic inclusion sulfide or oxide will cause the steel in the hot rolling process to produce a weak layer, resulting in the mechanical performance of the product, this rare earth inclusion during rolling will not be deformed, so give the fine grain of the final product with good performance. Cerium oxide is often added to molten steel in the form of a cerium-rich mix of rare-earth metals, where the cerium combines with oxygen and sulfur to produce cerium oxides and cerium oxides with high melting points and hardness to avoid the formation of other oxides and sulfides of poor performance.