904L stainless steel seamless tube

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904L stainless steel seamless tube. 904L is also known as UNS N08904, DIN 1.4539, SUS 890L, 015Cr21Ni26Mo5Cu2. Chemical composition: Elements – C, Si, Mn, Cr, Ni, S, P, Mo, N, Cu; contents: ≤0.02, ≤1.0, ≤2.0, 19.0–23.0, 23.0–28.0, ≤0.03, ≤0.04, 4.0–5.0, ≤0.10, 1.0–2.0. Mechanical properties: Tensile strength, yield strength, elongation, hardness – ≥490, ≥220, ≥35 HB, ≤187. Physical properties: Density 8.0 g/cm3, melting point 1300°C–1390°C. Product characteristics: 904L is a super austenitic stainless steel that is low-carbon, high-nickel and molybdenum content; it belongs to the category of acid-resistant austenitic stainless steels. It is a proprietary material developed by the French company H·S. It exhibits excellent activation-passivation transition capabilities, as well as very good corrosion resistance. It shows good resistance to corrosion in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid, and phosphoric acid. It also possesses good pitting resistance in neutral chloride-containing media, along with excellent resistance to crevice corrosion and stress corrosion. It is suitable for sulfuric acids of various concentrations at temperatures below 70°C, and it also exhibits excellent corrosion resistance in acetic acid and formic acid of any concentration and at any temperature, as well as in mixtures of acetic acid and formic acid, under normal pressure. Since the carbon content of 904L is very low (up to 0.020%), no carbides will precipitate under normal heat treatment and welding conditions. This eliminates the risk of intergranular corrosion that occurs after conventional heat treatment and welding. Due to its high chromium, nickel, and molybdenum content, as well as the addition of copper, 904L can be passivated even in reducing environments such as sulfuric acid and formic acid. Its high nickel content results in a low corrosion rate even when it is in an active state. In pure sulfuric acid within a concentration range of 0–98%, the operating temperature for 904L can reach up to 40 degrees Celsius. Pure phosphoric acid exhibits excellent corrosion resistance in the concentration range of 0–85%. In industrial phosphoric acid produced by the wet process, impurities have a strong impact on corrosion resistance. Among all types of phosphates, 904L has better corrosion resistance than ordinary stainless steel. In strongly oxidizing nitric acid, 904L has lower corrosion resistance compared to highly alloyed steel grades without molybdenum. In hydrochloric acid, the use of 904L is limited to lower concentrations of 1-2%. Within this concentration range. The corrosion resistance of 904L is better than that of conventional stainless steels. 904L steel has a high resistance to pitting corrosion. It also exhibits excellent resistance to crevice corrosion in chloride solutions. The high nickel content of 904L reduces the corrosion rate in pits and crevices. Ordinary austenitic stainless steels may be susceptible to stress corrosion in a chloride-rich environment at temperatures above 60 degrees Celsius; increasing the nickel content of the stainless steel can reduce this susceptibility. Due to its high nickel content, 904L exhibits excellent resistance to stress corrosion cracking in chloride solutions, concentrated hydroxide solutions, and environments rich in hydrogen sulfide. Matching welding materials: electrodes (E385-16/17), wire (ER385). Common application fields of 904L stainless steel seamless pipes*: Petroleum and petrochemical equipment, such as reactors in petrochemical facilities. * Equipment for the storage and transportation of sulfuric acid, such as heat exchangers. * The flue gas desulfurization equipment in power plants is mainly used in components such as the tower body of the absorption tower, flues, damper plates, internal components, and the spraying system. * Washers and fans in the organic acid treatment system. *Seawater treatment equipment, seawater heat exchangers, papermaking industry equipment, sulfuric acid and nitric acid production equipment, acid and pharmaceutical manufacturing industries as well as other chemical processing equipment, pressure vessels, food processing equipment. *Pharmaceutical factories: centrifuges, reactors, etc. *Plant-based foods: soy sauce jars, cooking wine, salt jars, equipment, and dressings. *904L is a suitable steel grade for highly corrosive media such as dilute sulfuric acid. Production process: cold drawing/cold rolling. Product shapes: round tubes, square tubes, rectangular tubes, oval tubes, etc