What you must know about 2205 duplex stainless steel

What you must know about 2205 duplex stainless steel

2205 duplex stainless steel is a (austenitic-ferrite) duplex stainless steel composed of 22% chromium, 3% molybdenum and 4.5% nickel-nitrogen alloy (referred to as 2205 duplex steel). 2205 duplex stainless steel is a nitrogen-added duplex stainless steel that has high strength, good impact toughness, and good overall and local stress corrosion resistance. 2205 Duplex Steel is particularly suitable for use in the -50°F/+600°F temperature range. This alloy may also be considered for applications outside this temperature range.

The main feature of 2205 duplex stainless steel is that the yield strength can reach 400-550MPa, which is twice that of ordinary austenitic stainless steel. This feature allows designers to reduce weight when designing products, so they can save materials. This alloy is stronger than 316 and 317L It also has a price advantage and reduces equipment manufacturing costs. In terms of corrosion resistance, especially in harsh medium environments (such as seawater, high chloride ion content), the resistance to pitting corrosion, crevice corrosion, stress corrosion and corrosion fatigue of duplex stainless steel is significantly better than that of ordinary austenite. Stainless steel, comparable to high-alloy austenitic stainless steel.

Due to the special performance characteristics of 2205 dual-phase steel, the product categories include bars, wires, welded pipes, seamless pipes, steel plates, forgings, strips, etc., with a wide range of applications. It is currently the most widely used brand among duplex steels. .

1. Physical and mechanical properties of 2205 duplex stainless steel

Density: 8.0g/cm3.

Tensile strength: σb≥620Mpa.

Yield strength: σ0.2≥450Mpa

Elongation: δ≥25%.

2. Corrosion resistance of 2205 duplex stainless steel

1. Uniform corrosion: Due to the chromium (22%), molybdenum (3%) and nitrogen content (0.18%) of 2205 dual-phase steel, the corrosion resistance of 2205 is better than 316L and 317L in most environments.

2. Local corrosion resistance: The content of chromium, molybdenum and nitrogen in 2205 dual-phase steel makes it highly resistant to pitting corrosion and crevice corrosion in oxidizing and acidic solutions.

3. Resistance to stress corrosion: The dual-phase microstructure of 2205 dual-phase steel helps improve the resistance of stainless steel to stress corrosion cracking. Under certain conditions of temperature, stress, oxygen and chloride, austenitic stainless steel will undergo chloride stress corrosion. Since these conditions are not easily controlled, the use of 304L, 316L and 317L is limited in this regard.

4. Anti-corrosion fatigue: The high strength and corrosion resistance of 2205 dual-phase steel make it have high anti-corrosion fatigue strength. Processing equipment is susceptible to corrosive environments and loading cycles, and the characteristics of 2205 are well suited for such applications.

3. 2205 duplex stainless steel structure

The chemical composition of 2205 dual-phase steel can achieve an ideal microstructure of 50 α / 50 γ after solid solution annealing at 1900°/1922°F (1040°/1080°C).

4. Application fields of 2205 duplex stainless steel

2205 duplex steel application fields: neutral chloride environment, oil refining industry, petrochemical and chemical industry, transportation pipelines for chemical industry, oil and natural 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, hood desulfurization, osmotic desalination and desalination equipment, sulfuric acid plants, marine engineering fasteners, etc.