S31803 Duplex Steel Grade, Characteristics and Applications

S31803 Duplex Steel Grade, Characteristics and Applications

S31803 material grade: S31803 duplex steel, Swedish grade: 2205, German grade: 1.4462, Chinese grade: 00Cr22ni5Mo3n, F51

S31803 duplex steel is a new product successfully developed in 2000. S31803 duplex steel is a nitrogen-added duplex stainless steel (referred to as 2205 duplex steel). S31803 duplex steel is a duplex stainless steel composed of 21% chromium, 2.5% molybdenum and 4.5% nickel-nitrogen alloy. The current domestic S31803 duplex steel products include welded pipes, seamless pipes, steel plates, bars, forgings, strips, etc. Early duplex stainless steel can resist medium-intensity uniform corrosion and chlorine stress corrosion cracking, but its performance will be greatly reduced when used in welding. In order to improve this situation, nitrogen was added to S31803 duplex steel, so that 1.4529 not only improves corrosion resistance, but also has good welding conditions. It has high strength, good impact toughness and good overall and local stress corrosion resistance.

The yield strength of S31803 duplex steel is twice that of austenitic stainless steel. This feature allows designers to reduce weight when designing products, making this alloy more cost-effective than 316 and 317L. This alloy is particularly suitable for applications in the -50°F/+600°F temperature range. For applications outside this temperature range, this alloy can also be considered, but there are some restrictions, especially when applied to welded structures. Due to the special performance characteristics of 2205 duplex steel, it has a wide range of applications and is still the most widely used grade among duplex steels.

The chemical composition of S31803 Duplex Steel achieves the desired microstructure of 50 α / 50 γ after solution annealing at 1900°/1922°F (1040°/1080°C). Heat treatment above 2000°F may result in an increase in the ferrite content. Like other duplex stainless steels, 2205 Duplex Steel is susceptible to the precipitation of intermetallic phases. Intermetallic phases precipitate between 1300°F and 1800°F, with the fastest precipitation rate at 1600°F. Therefore, we need to test S31803 Duplex Steel to ensure the absence of intermetallic phases. The test refers to ASTM A923.

Application areas of S31803 duplex stainless steel: Application areas of S31803 duplex steel: neutral chloride environment, oil refining industry, petrochemical and chemical industry, chemical industry pipelines, oil and gas industry, pulp and paper industry, fertilizer industry, urea industry, phosphate fertilizer industry, seawater environment, energy and environmental protection industry, light industry and food industry, food and pharmaceutical industry equipment, high-strength structural parts, submarine pipelines, smoke exhaust fan desulfurization, osmotic desalination equipment, sulfuric acid plants, marine engineering fasteners, etc.