With the development of science and technology, the application of molybdenum and molybdenum alloys in high-tech and other fields has also continued to expand. Next, let's take a look at the application of molybdenum and its alloys.
1. Steel industry
According to the statistics of molybdenum consumption in various countries in the world, the application of molybdenum in the steel industry still occupies the most important position. As an alloying element of steel, molybdenum can improve the strength of steel, especially high-temperature strength and toughness; improve the corrosion resistance of steel in acid-base solutions and liquid metals; improve the wear resistance of steel and improve hardenability and weldability And heat resistance. Molybdenum is a good element that forms carbides. It will not be oxidized during the steelmaking process. It can be used alone or in combination with other alloying elements.
Molybdenum is used together with chromium, nickel, manganese and silicon to produce different types of stainless steel, tool steel, high-speed steel and alloy steel. The made stainless steel has good corrosion resistance and can be used for corrosion-resistant steel pipes in petroleum exploitation, automobile shells, sewage treatment equipment, etc. A stainless steel with about 6% molybdenum can also replace titanium for seawater desalination devices, ocean-going ships, offshore oil and natural gas extraction pipelines.
The molybdenum series high-speed steel has the advantages of uneven carbide, wear resistance, good toughness, and strong high temperature plasticity. It is suitable for manufacturing forming tools. Molybdenum alloy steel can be used to manufacture machine tool structural parts, industrial vehicles and bulldozing equipment.
2. Agricultural fertilizer
Molybdenum is one of the necessary "trace elements" in plants, which can significantly improve the quality and yield of legumes, pastures and other crops. Therefore, fertilizers often contain ammonium molybdate. Molybdenum can promote the fixation of nitrogen in the air by rhizobia and other nitrogen-fixing organisms, and can further transform nitrogen into protein required by plants; molybdenum can promote the absorption of phosphorus by plants and play its role in plants; molybdenum can accelerate plants The formation and transformation of carbohydrates in the body increase the content and stability of plant chlorophyll and increase the content of vitamin C. Not only that, molybdenum can also improve the drought and cold resistance and disease resistance of plants.
The application of molybdenum fertilizer is characterized by low dosage, high yield, and low cost. It is an important measure to improve agricultural harvests, especially soybean harvest.
3. Electronic and electrical
Molybdenum has good electrical conductivity and high temperature performance, especially the thermal expansion coefficient of glass is very close, so it is widely used in the core wire, lead wire, side rod and other parts of the spiral filament in the bulb, and used as the grid and anode support material in the electron tube .
In ultra-large-scale integrated circuits, molybdenum is used as a metal oxide semiconductor gate, and the "bimetal effect" can be eliminated by mounting integrated circuits on molybdenum; ultra-thin seamless molybdenum tubes (about 15μm) can be used as high-definition televisions The anode bracket of the machine picture tube, the image scanning line of this kind of TV is 1,125, which is twice as high as that of the ordinary TV; the molybdenum wafer can also be used as the substrate and heat sink of the power transistor heat shield and silicon rectifier. In addition to the use of pure molybdenum in the modern electronics industry, Mo-Re alloys can be used as structural materials for electron tubes and special bulbs, and Mo-50Re and TZM alloys can also be used as structural components for thermionic cathodes in high-power microwave tubes and millimeter wave tubes.
4. Car spraying
The melting point of molybdenum is as high as 2620℃, and it has good high-temperature performance and corrosion resistance, and has a strong bonding force with steel. Therefore, it is the main thermal spray material in the production of automobile parts. Thermal spray materials can significantly improve the performance of piston rings, synchronizing rings, shift forks and other worn parts, and are also used to repair worn crankshafts, rolls, shafts and other mechanical parts.
5. High temperature components
Molybdenum's high purity, good high temperature resistance, and low vapor pressure make it often used to make heating elements and structural materials for high-temperature furnaces. Molybdenum has good ablation resistance in molten quartz, and is often used as an electrode for energization in the glass industry, with a service life of more than one year. In addition to being used as an electrode, molybdenum can also be used as a high-temperature structural material for glass melting, such as channels and pipes. The use of molybdenum instead of platinum on the glass fiber drawing furnace has a good effect and greatly reduces the production cost. In addition, molybdenum and its alloys can also be used for hot isostatic pressing, heat shields, sintering and steaming paint boats, etc.
Molybdenum silicide is a widely used material for electric heating components. It has the characteristics of high temperature oxidation resistance, excellent corrosion resistance and high melting point, and has a long life.
6. Oil extraction
Molybdenum can not only be used in oil and gas field drilling pipelines, but also often combined with cobalt and nickel as a catalyst for petroleum refining pretreatment, mainly for the desulfurization of petroleum, petrochemical products and liquefied coal. During the hydrogen treatment process. Sulfide will react with hydrogen on the surface of the catalyst, so that sulfide ions will be released in the form of hydrogen sulfide, and at the same time, nitrogen and metal impurities in the crude oil will be eliminated to reduce the poisoning of these impurities to other catalysts during petroleum refining, thereby improving Product color, smell and improve its stability. After passivation, a layer of carbon remains on the surface of the molybdenum-based catalyst. If the carbon layer is burned off, the catalyst can restore its activity, and the life span can be 1-5 years. Molybdenum plays an important role in petroleum cracking and reforming, and is an ideal electron donor and carrier.
In addition to the above-mentioned uses, molybdenum and its alloys can also be used in fields such as nuclear industry, aerospace, and environmental protection.