What elements are rare earth alloys and their role in wear resistant steel
types of rare earth alloy elements rare earth elements belong to lanthanide elements in the periodic table, with atomic numbers ranging from 57 to 71. It usually includes 17 elements with very similar chemical properties, such as yttrium (y) and scandium (SC). Among them, La (lanthanum), Ce (cerium), PR (praseodymium) and Nd (neodymium) are classified as light rare earths. The other 13 elements are classified as heavy rare earths. The common chemical symbol of rare earths is re (rare earth).
the action of rare earth alloy elements. Adding rare earth into liquid steel will produce a series of metallurgical process behaviors, which can be summarized as purifying liquid steel, such as deoxidation and desulfurization, Remove the gas (H2, N2) of the steel grade, make the composition tend to be uniform, reduce dendrite segregation, improve the morphology, size and distribution of metal inclusions, and refine the grains. Therefore, the inclusion shape can be changed after adding rare earth into the steel (spherical) makes the inclusions become fine and dispersed in the crystal. The addition of rare earth improves the shape, size and distribution of sulfide inclusions, contributes to the improvement of metallurgical quality and brings benefits to many service properties.
rare earth alloys also have a significant effect on the crystalline grains. It is found that the addition of rare earth can refine the grains, inhibit the development of columnar regions, and even eliminate columnar regions. The reasons for grain refinement of rare earth are as follows: rare earth is a surface active element, which reduces the surface tension of liquid steel and hinders grain growth; Rare earth inclusions can be used as non spontaneous nucleation core to promote nucleation and refine grains; The hydrogen fixation of rare earth eliminates the tiny hydrogen bubbles as the leading phase for the development of columnar crystals and hinders the growth of columnar crystals.
