Precision seamless steel pipe is a kind of high precision steel pipe after cold rolling or cold drawing. Because the precision seamless steel pipe has the advantages of no oxide layer on the inner and outer walls, no high pressure, high precision, high precision machining, no cold bending deformation, expansion, flatness, and no cracks, it is mainly used for pneumatic or hydraulic components such as gas cylinders or oil cylinders. All are seamless steel pipes. The chemical composition of precision seamless steel pipes includes silicon carbide, manganese, sulfur, phosphorus, and chromium. The corrosion resistance of U 304 seamless steel pipe depends on the alloying elements contained in it. Chromium is the basic element for obtaining corrosion resistance of stainless steel. When the chromium content reaches about 12%, chromium interacts with oxygen in the corrosive medium and forms a thin oxide film (self-passivation film) on the surface, which can prevent it. The substrate progresses to corrosion. In addition to chromium, nickel, molybdenum, titanium, niobium, copper, nitrogen, etc. are commonly used as alloying elements in stainless seamless steel pipes to meet the requirements for stainless steel and performance in various applications. y Sanya thick-walled seamless steel pipe material classification and quenching and tempering specification: quenching temperature 850 ± 10 ℃, oil cooling; tempering temperature 520 ± 10 ℃, water and oil cooling. The inner diameter of C Neijiang's fake and inferior tubes fluctuates greatly due to the following reasons: l The temperature is unstable and has a yin and yang face. The composition is uneven. Due to the poor equipment and low foundation strength, the rolling mill jump is large. There will be large changes within the same week, such tendons are uneven and easy to break. Fs2, cold rolling, degreasing, cutting, air-drying, internal polishing, external polishing, inspection, marking, packaging of finished products. 16Mn seamless steel pipe is a low-alloy high-strength structure with a carbon content of 0.1% -0.25%. Adding silicon, vanadium, niobium and titanium, the total alloy content is 3%. It is divided into four levels of 300, 350, 400 and 450mpa according to the intensity. Mainly q29, q34, Q390, Q420 and Q460. : Q & rdquo; is the uppercase Chinese pinyin letter of the word "Qu", followed by the brand's small yield point (& sigma; s) value, and then according to the content of impurity elements (sulfur, phosphorus) from high to low and carbon and manganese Change the symbol while setting, it is divided into D and so on. Among them, B grade is usually called 16Mn seamless steel pipe, chemical composition is C: 0.12 ~ 0.20; Mn: 20 ~ 60; Si: 0.20 ~ 0.5; tensile strength 470 ~ 660N / mm ~ 2; yield strength 275 ~ 345N / mm ~ 2; elongation is 21%. The adjustment of perforation temperature and perforation process cannot be ignored. If the perforation temperature is low, improper adjustment will also cause the inside of the capillary. q345d seamless steel pipe is a long bar with a hollow section and no seams around it. The hardness test of Cp16Mn structural pipe is a simple and easy mechanical performance test. In order to replace some mechanical performance tests with hardness tests, a more accurate conversion relationship between hardness and strength is needed in the good.
321 stainless steel pipe: high-quality carbon structure, alloy structure and stainless heat-resistant seamless steel pipe mainly used for steam boiler pipes with high pressure and above. These boiler pipes work under high temperature and high pressure. Oxidation and corrosion can also occur under the action of high temperature flue gas and water vapor. Therefore, the pipe is required to have high durability, high oxidation resistance, and good stability. Hydraulic prop pipe. z High-pressure seamless steel pipe for chemical fertilizer equipment (GB 79-2000) is a high-quality carbon structure and alloy seamless steel pipe suitable for chemical equipment and pipelines with an operating temperature of -40 ~ 400 ℃ and an operating pressure of 10 ~ 30Ma. J-coated pipes include galvanized pipes, aluminized pipes, chrome-plated pipes, aluminized pipes, and other alloyed pipes. M Click to view 16Mn is a low alloy high strength structure with a carbon content of 0.1% -0.25%. Manganese, silicon, vanadium, niobium, titanium and other main alloying elements are added, and the total alloy content is 3%. It is divided into four levels of 300, 350, 400 and 450mpa according to the intensity. qG is divided into hot rolled () seamless steel pipe and cold drawn (rolled) seamless steel pipe due to different processes. Cold drawn (rolled) pipe is divided into two kinds of round pipe and special-shaped pipe. Seamless steel tubes are divided according to good standards: national standard seamless steel tubes, Japanese standard seamless steel tubes, British seamless steel tubes, American standard seamless steel tubes, European standard seamless steel tubes, and non-standard seamless steel tubes. Bl 304 stainless steel pipe is widely used as stainless heat-resistant, food equipment, general chemical equipment, atomic energy industry equipment.
Since last year, there have been frequent reports of "double-reverse" on stainless foundry products abroad, which has a great impact on the stainless foundry industry. Exports are the majority of the development of the stainless industry China has a huge market share. In the face of an economic downturn and a slowing development rate, the development of the stainless industry should continuously improve product quality, better develop overseas trade and respond to trade protection. Combining environmental protection, energy resources, and the human environment to enhance the competitiveness of stainless products, only in this way can we gain an unbeatable position in foreign trade. High-quality and cheap q Hot-rolled (seamless steel pipe): round pipe billet → heating → perforation → roll diagonal rolling, continuous rolling or → de-pipe → sizing (or reduction) → cooling → billet pipe → straightening → hydraulic pressure Test (or flaw detection) → mark → storage. XQ345E: C ≤ 0.1 Mn ≤ 70, Si ≤ 0.50, P ≤ 0.02 S ≤ 0.020, Al ≥ 0.0 304 seamless steel pipe has no sand holes, no sand holes, no black spots, no cracks, and a flat weld bead. Bending, cutting, welding process performance advantages, the advantages of stable nickel content. b The difference between Sanya 16mn seamless steel pipe 8162 and 8163 The difference between GB8162 seamless steel pipe and GB8163 seamless steel pipe: GB8162 "Seamless steel pipe for structure", Sanya 45 # seamless steel pipe, Sanya precision rolled bright seamless pipe, Sanya cold rolled Precision steel pipe, this standard applies to general structural mechanical structures; GB8163 "Seamless steel pipe for fluid transmission", this standard applies to general seamless steel pipe for fluid transmission. The main difference from GB8162 is that GB8163 pipe is tested hydraulically or one by one. Ultrasonic, eddy current and magnetic leakage detection, so in the selection of pressure pipeline standards, it is not appropriate to use the GB8162 standard. kF For the external export difficulties, the stainless industry is required, but the important thing is that the stainless industry must continuously improve its quality level and carry out a comprehensive upgrade. High alloys that can corrode in air or chemically corrosive media must contain more than 12% chromium in order to maintain the inherent corrosion resistance of stainless. 304 stainless chemical composition: Specification C Si Mn PS Cr Ni (nickel) Mo SUS304 ≤0.08 ≤ 00 ≤ 00 ≤0.05 ≤0.03 1 00-20.0025 ~ 50. Dk pipes are further divided into equal section pipes and variable section pipes according to their profile shapes. Variable cross-section (or variable cross-section) pipe refers to pipes that undergo periodic or non-periodic changes in the shape of the cross-section, inner and outer diameters, and wall thickness along the length of the pipe. It mainly includes: outer tapered pipe, inner tapered pipe, outer stepped pipe, inner stepped pipe, periodic section pipe, corrugated pipe, spiral pipe, pipe with fins, and pipe with multiple wires.