What are the four categories of stainless steel bolts?
The trade name of PTFE is “Teflon”, simple PTFE or F4, commonly known as the king of plastics. It is one of the most corrosion-resistant materials in the world today. It is used to manufacture liquid gas pipelines, heat exchangers and other content equipment connections. Ideal sealing material.
Tetrafluoroethylene is one of the best corrosion resistance materials in the world today, so it has the reputation of “Plastic King”. It can be used in any kind of chemical medium for a long time, and its production has solved many problems in my country’s chemical, petroleum, pharmaceutical and other fields. Teflon seals, gaskets, gaskets. Polytetrafluoroethylene seals, gaskets, and sealing gaskets are made of suspension polymerized polytetrafluoroethylene resin. Compared with other plastics, PTFE has the characteristics of excellent chemical resistance and temperature resistance. It has been widely used as a sealing material and filling material.
It is a polymer compound formed by polymerization of tetrafluoroethylene. It has excellent chemical stability, corrosion resistance, airtightness, high lubrication, non-stickiness, electrical insulation and good resistance to aging. It can work for a long time at a temperature of +250℃ to -180℃. Except for molten metal sodium and liquid fluorine, it can withstand all other chemicals. It will not change when boiled in aqua regia.
At present, all kinds of PTFE products have played a pivotal role in the national economy such as chemical industry, machinery, electronics, electrical appliances, military industry, aerospace, environmental protection and bridges. stainless steel screw
2. Carbon fiber
Carbon fiber is a fibrous carbon material with a carbon content of more than 90%. The C/C composite material composed of it and resin is one of the most corrosion-resistant materials.
Carbon fiber is a new type of high-strength, high-modulus fiber with a carbon content of more than 95%. It is a microcrystalline graphite material obtained by piling up flake graphite microcrystals and other organic fibers along the fiber axial direction, and undergoing carbonization and graphitization treatments. Carbon fiber is “flexible on the outside and rigid on the inside”. Its quality is lighter than that of metal aluminum, but its strength is higher than that of steel. It also has the characteristics of corrosion resistance and high modulus. It is an important material in national defense, military and civilian applications. It not only has the inherent characteristics of carbon materials, but also has the soft processability of textile fibers. It is a new generation of reinforcing fibers.
Carbon fiber has many excellent properties. Carbon fiber has high axial strength and modulus, low density, high specific performance, no creep, ultra-high temperature resistance in a non-oxidizing environment, good fatigue resistance, and its specific heat and electrical conductivity are between non-metallic and non-metallic. Among metals, the coefficient of thermal expansion is small and anisotropic, the corrosion resistance is good, and the X-ray transmission is good. Good electrical and thermal conductivity, good electromagnetic shielding, etc.
Compared with the traditional glass fiber, the Young’s modulus of carbon fiber is more than 3 times; compared with Kevlar fiber, the Young’s modulus is about 2 times, and it does not swell or swell in organic solvents, acids, and alkalis. Outstanding corrosion resistance.
3. copper oxide
Copper oxide is currently the most corrosion-resistant material. Sweden has always been a world leader in the field of nuclear waste disposal. Now the country’s technicians are using a new container made of copper oxide to store nuclear waste, which can guarantee safe storage for 100,000 years.
Copper oxide is a black oxide of copper, slightly amphiphilic and slightly hygroscopic. The relative molecular mass is 79.545, the density is 6.3~6.9 g/cm3, and the melting point is 1326℃. It is insoluble in water and ethanol, soluble in acid, ammonium chloride and potassium cyanide solution. It dissolves slowly in ammonia solution and can react with strong alkali. Copper oxide is mainly used to make rayon, ceramics, glazes and enamels, batteries, petroleum desulfurizers, pesticides, and also for hydrogen production, catalysts, and green glass.
Platinum is chemically stable and does not interact with hydrochloric acid, nitric acid, sulfuric acid and organic acids at room temperature. It is called the “most corrosion-resistant metal”, but it is soluble in aqua regia. Titanium is easy to form a stable protective film of titanium oxide, so the titanium cooling tube is considered to be free from corrosion and erosion.
Platinum is a naturally occurring white precious metal. Platinum flashed a dazzling light in the history of human civilization as early as 700 BC. In the more than 2,000 years of human use of platinum, it has always been regarded as one of the most precious metals.
The nature of platinum is very stable, it will not deteriorate or fade due to daily wear, and its luster is always the same. Even if it comes into contact with common acidic substances in life, such as sulfur in hot springs, bleach, chlorine in swimming pools, or sweat, it will not be affected, so you can wear platinum jewelry with confidence at any time. No matter how long it is worn, platinum can always maintain its natural pure white luster and will never fade.
Post time: Sep-24-2021