Seamless steel pipes have hollow sections and are widely used as pipelines for transporting fluids, such as pipelines for transporting oil, natural gas, coal gas, water and certain solid materials.
Seamless steel pipes have hollow sections and are widely used as pipelines for transporting fluids, such as pipelines for transporting oil, natural gas, coal gas, water and certain solid materials. It is an economical cross-section steel that is widely used to make structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames, and steel scaffolding used in construction. Steel pipes are used to make ring-shaped parts, which can improve material utilization and simplify The manufacturing process saves materials and processing hours, such as rolling bearing rings, jack sets, etc., which have been widely manufactured with steel pipes. Seamless steel pipes can be divided into:
Structural tubes. This standard applies to seamless steel pipes for general structures and mechanical structures. The fluid seamless steel pipe standard applies to general seamless steel pipes for transporting fluids. The main difference between it and structural seamless steel pipes is that fluid seamless steel pipes undergo hydraulic testing or ultrasonic, eddy current, and magnetic flux leakage testing one by one. Therefore, in the standard selection of pressure pipeline steel pipes, it is not suitable to use fluid seamless steel pipes. Seamless steel pipes are represented by outer diameter and wall thickness. Thick-walled seamless steel pipes are mainly used for dry mechanical processing, coal mines, hydraulic steel, and other uses. The materials of thick-walled seamless steel pipes are divided into 10#20#35#45#16Mn27siMn.12Cr1MoV.10CrMo10 and 15CrMo35CrMo. Classification of thick-walled seamless steel pipes - hot-rolled thick-walled seamless steel pipes, cold thick-walled seamless steel pipes, cold-drawn thick-walled seamless steel pipes, extruded thick-walled seamless steel pipes, and jacking pipes. Stainless steel seamless steel pipes for structural use are hot-rolled (extruded, expanded) and cold-drawn (rolled) stainless steel made of corrosion-resistant pipes and structural parts and parts that are widely used in chemical, petroleum, textile, medical, food, machinery and other industries. ) seamless steel pipe.
1. Fluid pipes are pipes specially used to transport media with fluid properties. Media with fluid properties, in addition to liquid media such as water, oil, and solutions, solid media such as cement, grain, and coal powder can also flow under certain conditions. Fluid tubes can be made of steel, non-ferrous metals such as copper and titanium, or even non-metallic materials such as plastic. The fluid pipe must have a hollow cross-section, but it can also be square, triangular or any other shape. Some equipment is limited by parts and must use rectangular pipes, but the vast majority still use round pipes. The circular tube has the smallest circumference/area ratio among all geometric cross-sections, that is, the largest internal cross-section can be obtained with the same amount of material.
2. High pressure boiler tube.
High-pressure boiler tube is a type of boiler tube and belongs to the category of seamless steel tube. The manufacturing method is the same as that of seamless pipes, but there are strict requirements for the type of steel used in manufacturing steel pipes. High-pressure boiler tubes are often exposed to high temperature and high pressure conditions during use. Under the action of high-temperature flue gas and water vapor, the tubes will oxidize and corrode. Steel pipes are required to have high lasting strength, high resistance to oxidation and corrosion, and good structural stability. High-pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, air guide tubes, main steam tubes, etc. for high-pressure and ultra-high-pressure boilers.
3. Alloy pipe is a type of seamless steel pipe. Alloy pipe is divided into structural seamless pipe and high-pressure heat-resistant alloy pipe. Mainly different from the production standards of alloy pipes and its industry, annealing and tempering of alloy pipes changes its mechanical properties. achieve the required processing conditions. Its performance is higher than that of ordinary seamless steel pipes in terms of variable utilization. The chemical composition of alloy pipes contains more Cr, and it has high temperature resistance, low temperature resistance and corrosion resistance. Plain carbon seamless pipes contain no or very little alloy components. The reason why alloy pipes are widely used in petroleum, aerospace, chemical, electric power, boiler, military and other industries is because the mechanical properties of alloy pipes are highly variable and easy to adjust.
5.Petroleum cracking pipe
Petroleum cracking pipe is a long steel material with a hollow section and no seams around it. Petroleum cracking pipe is an economical steel material. It is widely used to manufacture structural parts and mechanical parts, such as oil drill pipes, automobile drive shafts, bicycle frames and steel scaffolding used in construction, etc. It is suitable for drying oil, furnace tubes, heat exchanger tubes and pipelines in refineries. Seamless steel pipe.
6. Low and medium pressure boiler tubes
It is made of steel ingots or solid tube blanks through perforation and then hot-rolled, cold-rolled or cold-drawn. Mechanical properties of low and medium pressure boiler tubes: Tensile strength σb (MPa): ≥ 410 (42) Yield strength s (MPa): ≥ 245 (25) Elongation 5 (%): ≥ 5 Sectional shrinkage (%) >5 Hardness: not heat treated<156HB, sample size: sample size 25mm Heat treatment specifications and metallographic structure: Heat treatment specifications: normalizing, 910°C, air cooling. Metallographic structure: ferrite + pearlite. 7-pressure prop pipe Hydraulic prop pipe is based on high-quality carbon structural steel, with one or several alloy elements appropriately added to improve the strength, toughness and quenching performance of the steel. After this type of steel is made, it usually needs to undergo heat treatments such as quenching and tempering, chemical heat treatment, and surface quenching. Compared with high-quality carbon structural steel, it has good comprehensive mechanical properties. It is often rolled into round, square, and shaped steel products and used as important structural parts in machinery or machines. The corrosion resistance of the hydraulic support pipe itself is not stainless steel, and of course the corrosion resistance is not good. But its wear resistance and cutting performance are much better than stainless steel.
