Yttrium, chemical symbol Y. It is one of the rare earth metal elements and a gray metal. The density is 4.4689g/cm3, the melting point is 1522 ℃, the boiling point is 3338 ℃, and the common valence is+3. The first ionization energy is 6.38 electron volts. It can react with hot water and is easily soluble in dilute acid. Special glass and alloy can be made.
Yttrium, chemical symbol Y. It is one of the rare earth metal elements and a gray metal. The density is 4.4689g/cm3, the melting point is 1522 ℃, the boiling point is 3338 ℃, and the common valence is+3. The first ionization energy is 6.38 electron volts. It can react with hot water and is easily soluble in dilute acid. Special glass and alloy can be made.
brief introduction
Yttrium is a rare earth element. Rare earth elements refer to scandium, yttrium and all lanthanide elements. Because of their rare content of yttrium in the crust, their oxides are similar to native elements such as calcium oxide, so they are named. It is difficult to discover, separate and analyze the rare earth elements because of their scattered distribution, often disorderly mineralization, and their very similar properties. Yttrium and cerium, another rare earth element, are the two elements with large content in the crust, so they were first found in rare earth elements. Norway and Sweden on the Scandinavian Peninsula in northern Europe are rich in rare earth element minerals, so these two elements were first discovered in this area.
The metal yttrium (element symbol Y) is a heavy rare earth metal element. It lies in the five periods of the third group in the periodic table of elements. The physical and chemical properties of yttrium are similar to other rare earth metals, and it often coexists with rare earth minerals of other rare earth metals. It is an important heavy rare earth metal. Metal yttrium has many applications in nonferrous alloys, iron and steel, rare earth permanent magnets and military industries. The application in steel is:
1. In molten steel at high temperature, Y reacts with S, O2, P, C, N to form YS, Y2O3, YP, YC, YN and other compounds, improving the service properties of steel.
2. In molten steel, Y reacts with inclusions such as Al2O3 and MnS to form Y2O3 and YS, while Al2O3 and MnS become Mn and Al, which improves the comprehensive properties of steel.
3. Sometimes, Y can also be alloyed with steel to form new compounds, which is beneficial to the improvement of steel properties.
4. When Y ≤ 1.0% is added to cast iron, the eutectic temperature and solid solubility can be increased to improve the processability.
5. Adding Y 0.015-0.07% to 18-8 type stainless steel can obviously improve the resistance to pinhole corrosion, which is beneficial to the requirements of application environment.
6. Adding 0.3% Y to the heat-resistant steel can significantly reduce the oxidation rate of the steel at different temperatures, reduce the oxidation increment and improve the service life.
7. When 45 # steel is boronized by salt melting at 960 ℃, the penetration rate and penetration amount of boron can be increased by adding Y based rare earth compounds. Y also penetrates into the surface layer, which greatly improves the surface properties and corrosion resistance of the steel surface. The thickness of the penetration layer is increased by 22-25%, with better use effect and higher economic value.
8. The quenching crack and forging crack can be reduced and the heat treatment process can be simplified by adding Y in the production of seamless steel pipes for petroleum.
9. The addition of Y 0.02-0.05% in some high alloy stainless steels can significantly improve the thermoplasticity and processability of the materials.
