The purpose of the molybdenum
Black material:Alloy steel, stainless steel, tool steel and cast iron are the main application areas of palladium, and their production volume determines the demand for palladium, whose role in the above-mentioned steel is as follows:
Reduce the cooling rate to the appropriate value to obtain a hard mars tissue, thereby improving the strength, hardness and toughness of large cross-sectional components;
Reduce the brittleness of the return fire;
Anti-hydrogen brittle;
Stress cracking caused by anti-sulphide;
Improve the strength of high temperature;
Improve the corrosion resistance of stainless steel, especially chloride pitting;
Improve the welding performance of high-strength, low-alloy steels.
Colored alloys:In most superalloys and many nickel- and titanium-based alloys, palladium is an important addition. At high temperature, radon can effectively accelerate solid reinforcement, prevent chloride pitting, and improve corrosion resistance in reducing fluid.
Palladium-based alloys:Radon and vanadium alloys are widely used because they have many characteristics, such as high strength (2000℃), low coefficient of thermal expansion, excellent thermal and electrical conductivity, molten glass, molten salt and molten metal have a high corrosion resistance, but also improve the wear resistance of thin coatings.
Palladium steel:Palladium is a special steel alloy element that not only brings many of its excellent properties into the steel, but is also easily added to the molten metal. Adding molybdenum oxide, molybdenum iron or scrap containing molybdenum to the steel can greatly reduce the melting loss.
Radon (0.15% to 0.30%) is used in carbon-penetrating steel to improve the hardenability of low-carbon parts of the heart and increase the toughness of high-carbon parts. This is especially effective for parts with large sections, such as gears. Radon is not oxidized during carbon seepage, and as an effective hardener, radon does not cause cracks and peeling of the surface.
High temperature steel:Compared with other alloying elements, the molybdenum atoms are very large. Therefore, it is a very effective reinforcement that increases the creep strength of the steel to the extent that it can be used at around 600℃. Its size effectively prevents the migration of arsenic atoms to the crystal boundary, thus preventing the receding brittleness. Hydrogen diffusion is also prevented and the degree to which hydrogen cracks is minimized.
One of the earliest high temperature steels to apply these properties is 0.50% C-Mo steel. It has been replaced by Cr-Mo series steels containing 0.50% to 2.0%. 2.25Cr-1.0% Mo Steel is a main alloy steel widely used in equipment for petroleum refineries, power plants and petrochemical plants.
High strength low alloy (HSLA) steel:Palladium has played an important role in the development of low-carbon microalloy HSLA steel. Add 0.1% to 0.3% of the molybdenum to fine-grain the needle-like ferritin grain tissue and enhance the precipitation hardening effect obtained from other alloying elements. Without intensive heat treatment, HSLA steel can achieve a high yield strength of 450 to 600MPa (65 to 85ksi). Because the plastic brittleness transition temperature is as low as -60℃, these materials are heavily used to build pipelines to distant Arctic oil and gas fields. Thinner-sized molybdenum-containing HSLA steels have good formability, and their high strength/weight ratio makes them ideal automotive component materials.
