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2205 stainless steel seamless tube. Material name: 2205; also known as UNS S32205, SAF2205, S22253, 022Cr23Ni5Mo3N. Chemical composition: C, Si, Mn, P, S, Cr, Ni, Mo, N. Standards: ≤0.03, ≤1.00, ≤2.00, ≤0.04, ≤0.03; 21.0–24.0%, 4.5–6.5%, 2.5–3.5%, 0.08–0.2%. Typical values: 0.025%, 0.6%, 1.5%, 0.026%, 0.0012%, 22.5%, 5.8%, 3.0%, 0.16%. Mechanical properties: Ys (MPa), Ts (MPa), El (%), Hv2.0t/2B. Standards: ≥450, ≥620, ≥18, ≤320. Typical values: 670, 875, 272, 80. Density (g/cm³); Magnetic property; Specific heat (J/g·°C); Thermal conductivity at 100°C (W/m·K); Coefficient of thermal expansion at 20–100°C (10/°C): 7.8; Magnetic property: 0.45; Specific heat: 19.0; Thermal conductivity: 13.7. Relevant standards: ASTM A312, ASTM A789, ASTM A790, GB13296, GB/T14976, etc； Product features: 1) Its yield strength is more than twice that of ordinary austenitic stainless steels, and it possesses sufficient plasticity and toughness for molding. Using duplex stainless steel to manufacture the walls of storage tanks or pressure vessels reduces the wall thickness by 30-50% compared to conventional austenitic steels, which helps to lower costs. 2) It possesses excellent resistance to stress corrosion cracking; even the duplex stainless steels with the lowest alloy content have a higher resistance to stress corrosion cracking than austenitic stainless steels, especially in environments containing chloride ions. Stress corrosion is a prominent problem that is difficult to address in conventional austenitic stainless steels. 3) The corrosion resistance of 2205 duplex stainless steel, which is the most widely used in many media, is superior to that of conventional 316L austenitic stainless steel. Super duplex stainless steel possesses extremely high corrosion resistance; in some media such as acetic acid and formic acid, it can even replace highly alloyed austenitic stainless steels as well as corrosion-resistant alloys. 4) It possesses good resistance to localized corrosion; compared with austenitic stainless steels with similar alloy contents, it exhibits superior performance in terms of wear corrosion and fatigue corrosion resistance. 5) It has a lower linear expansion coefficient than austenitic stainless steels and is close to that of carbon steel, making it suitable for joining with carbon steel; this holds significant engineering importance, such as in the production of composite sheets or linings. 6) Under both dynamic and static loading conditions, austenitic stainless steel possesses a higher energy absorption capacity; this gives biphasic stainless steel a clear advantage in enabling structural components to withstand sudden accidents such as collisions and explosions, making it practically useful. Disadvantages: Compared to austenitic stainless steels, the disadvantages of duplex stainless steels are as follows: 1) Their versatility and range of applications are limited compared to austenitic stainless steels; for example, their operating temperature must be kept below 250 degrees Celsius. 2) Its plasticity and toughness are lower than those of austenitic stainless steels, and its cold and hot working properties as well as formability are inferior to those of austenitic stainless steels. 3) There is a medium-temperature brittleness region; it is necessary to strictly control the heat treatment and welding procedures in order to prevent the formation of harmful phases that could degrade performance. Application areas: Widely used in ocean engineering, seawater treatment, mechanical instruments, oil and gas extraction and processing, as well as in heat exchanger equipment, devices, and pipelines for chemical transportation systems and the shipbuilding industry ； Methanol synthesis reactor ； Acrylamide crystallizer ； Polyacrylonitrile cooling coil ； Boat heating coil ； Sea water heat exchanger for soda ash production ； Vinyl chloride process towers, heat exchangers, vessels, and pipelines, etc.