Molybdenum is an important alloy additive in steel. According to 1986 statistics, it accounts for 83% of the world's total molybdenum consumption. And steel containing molybdenum accounts for 1/10 of the world's crude steel production. Therefore, molybdenum steel ratio is often used as one of the signs of a country's industrial development or not. The molybdenum steel ratio is 0.011% in the world, 0.014% in the United States, and 0.004% in China, which is less than half of the world average. The addition of molybdenum to steel is often divided into the following aspects:
Alloy steel: it consumes the largest amount of molybdenum, accounting for 44% of the world's total molybdenum consumption, accounting for more than half of steel added molybdenum. Structural steel (or general molybdenum steel) containing about 0.1%~ 0.2% molybdenum is widely used in skyscrapers, Bridges and other large steel components, can improve the steel hardness, strength and toughness, alloy steel analyzer to extend the life of these large facilities.
Molybdenum steel with 0.3% molybdenum is often used for load-bearing parts and transmission parts in transportation and automobile manufacturing. High strength alloy steel usually contains less than 0.3% molybdenum, 0.5%~ 3.5% nickel, 0.5%~1.0% chromium, to improve the hardness, strength and toughness of the steel, and has good weldability and corrosion resistance. At the end of 1970s, the Soviet Union used to develop the Tyumen oil field in Siberia to build the natural gas pipeline of 4300km in the alpine region, which cost 18kt of molybdenum. The construction of the second Siberian railway also took a lot of molybdenum.
Stainless steel: it accounts for about 22% of the total consumption of molybdenum, molybdenum is usually 4%~5%, often used for corrosion prevention, corrosion resistance. Such as petroleum refining, natural gas Wells and oil Wells in the highly corrosive places, aircraft engines, Marine equipment, stainless steel analyzer, chemical equipment... And so on.
High speed and tool steels: it accounts for about 8% of the total molybdenum consumption. The molybdenum content in high speed steel is usually 3.75%~9.5%, with an average of 4.8%, in which tungsten, vanadium, chromium and other metals are often added. There are 90% molybdenum in the high speed steel used in the world. Worldwide, about 6000t of molybdenum is used in the production of high speed steel each year. The molybdenum content of tool steel analyzer is usually 0.6%~ 2.95%, and the molybdenum used in tool steel is 2000~2500t worldwide every year.
Cast iron and rolls: their consumption accounts for 6% of the total molybdenum consumption. When 0.3%~ 1.0% molybdenum is added to cast iron, the tensile, bending and fatigue strength will be greatly improved, and the uniformity of casting structure will also be improved, which is especially important for large castings, which are widely used in automobile manufacturing, pressure pipes and molds.
