Molybdenum and molybdenum alloy plate and strip hot rolling lubricant
Molybdenum is a necessary trace element for human body, animals and plants. It is a silver-white metal, hard and tough. Due to the low temperature brittleness and welding brittleness of molybdenum alloy, and high temperature easy oxidation, so its development is limited. Molybdenum metal is gradually used in nuclear power, new energy and other fields. Due to the importance of molybdenum, governments regard it as a strategic metal, molybdenum in the early 20th century was widely used in the manufacture of weapons and equipment, modern high, fine, sharp equipment on the material requirements are higher, such as molybdenum and tungsten, chromium, vanadium alloy used in the manufacture of warships, rockets, satellite alloy components and parts.
Molybdenum and molybdenum alloys are widely used, because it has many characteristics, such as high strength, low coefficient of thermal expansion, excellent thermal and electrical conductivity, high corrosion resistance to molten glass, molten salt and molten metal, and can also improve the wear resistance of thin coatings.
Industrial production of molybdenum alloys molybdenum titanium zirconium, molybdenum tungsten and molybdenum rare earth alloys, the most widely used is the first class. The main strengthening ways of molybdenum alloy are solution strengthening, precipitation strengthening and work hardening. Molybdenum alloy sheet, strip, foil, tube, bar, wire and profile can be prepared by plastic processing, and its strength and low temperature plasticity can be improved. Molybdenum sheets are used to make radio equipment and X-ray equipment; Molybdenum is resistant to high temperatures. Molybdenum has two significant characteristics in rolling: first, the chemical properties are relatively active, so that in the rolling process, especially in the hot rolling process, it is easy to react with the surrounding environment and cause pollution, reduce the processing performance; Second, it is easy to stick to the roll. Therefore, in the rolling process of molybdenum material, it is necessary to choose an effective lubricant and lubrication method. Molybdenum and molybdenum alloy plate and strip hot rolling process requirements are: first, hot rolling heating temperature, because molybdenum and its alloy has a high melting point, high deformation resistance and powder metallurgy plate porous equiaxed grain structure, easy to lead to low temperature brittle; Therefore, the rolling blank must be heated to a very high temperature. The second is the hot rolling processing rate and hot rolling speed, due to the relatively narrow plastic temperature range of molybdenum and its alloy deformation resistance, the total processing rate needs to be completed after rolling, combined with multiple annealing, in order to prevent oxidation and improve productivity, under the conditions of rolling mill capacity, the total processing rate between two annealing should be increased as far as possible. The lubricant has a high adsorption capacity to ensure that a uniform continuous oil film is formed between the roll and the rolled piece, reducing the friction coefficient during the rolling process, reducing the adhesion of metal and tools, and has the performance of lubrication, cooling, cleaning and thermal oxidation stability.
