The metallurgical industry is one of the fields that use the rarest earth materials. Adding rare earth metals to steel can refine, desulfurize, neutralize low-melting-point harmful impurities, and improve the processing properties of steel; adding rare earth metals to non-ferrous alloys (such as magnesium, aluminum, copper, zinc, nickel, etc.) can improve the physical and chemical properties of the alloy and improve the mechanical properties of the alloy at room temperature and high temperature.

Rare earths as additives

Rare earth has the functions of purification, modification, and micro-alloying, which can reduce and improve the number, shape, and structure of the inclusions in the steel, thereby significantly improving the rigidity and toughness of steel, and improving the high-temperature oxidation resistance, hot workability and corrosion resistance of steel.

- Purify molten steel

Rare earth has the functions of deoxidation and desulfurization, which can reduce and refine the impurities in the steel. Adding rare earth to steel can replace O and S in manganese sulfide, alumina and aluminosilicate to form rare earth compounds. And these compounds can be filtered out in subsequent steps.

- Metamorphic inclusions

Similarly, the addition of rare earth to steel causes it to replace the elongated manganese sulfide to form spherical rare earth sulfides or oxysulfides. Relatively speaking, the morphology of the sulfide is controlled, thereby improving the toughness of steel, especially the transverse impact toughness, and improving the anisotropy of steel. Rare earths can also replace high-hardness alumina magazines to form spherical oxysulfides or rare earth aluminates, thereby significantly improving the fatigue resistance of steel.

- Microalloying

Rare earths have hydrogen trapping properties, which can improve the hydrogen-induced delayed fracture performance of steel; rare earths can improve the corrosion resistance, oxidation resistance, and fatigue resistance of steel.

Rare earths as spheroidizer

As a nodularizing agent, rare earth can neutralize the anti-nodularizing elements in the metal, thereby improving the mechanical properties, wear resistance, toughness, etc. of cast iron at high temperatures.