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Why should the service temperature of 2205 duplex stainless steel be controlled below 250?
2205

Material grade: 2205 dual-phase steel

American brand: UNS S3 1803

German brand: 1.4462

China brand: 00Cr22Ni5Mo3N, F5 1.

I overview of 2205(S3 1803, F5 1, 1.4462) duplex stainless steel:

2205(S3 1803, F5 1, 1.4462) dual-phase steel is a new product successfully developed in 2000. 2205 dual-phase steel is a kind of nitrogen-containing dual-phase stainless steel (2205 dual-phase steel for short), which is made of 2 1% chromium, 2. At present, domestic 2205 dual-phase steel products include welded pipe, seamless pipe, steel plate, bar, forged material, strip and so on. Early duplex stainless steel can resist uniform corrosion and chlorine stress corrosion cracking with moderate strength, but its performance will be greatly reduced when used in welding. In order to improve this situation, nitrogen is added to 2205 dual-phase steel, which not only improves the corrosion resistance, but also has good welding application. It has high strength, good impact toughness and good overall and local stress corrosion resistance.

The yield strength of Bing Zheng Industrial 2205 dual-phase steel is twice that of austenitic stainless steel, which enables designers to reduce the weight when designing products, and also makes this alloy more competitive than 3 16 and 3 17L. This alloy is especially suitable for the temperature range of-50 F/+600 F. For applications beyond this temperature range, this alloy can also be considered, but there are some restrictions, especially when it is applied to welded structures. Because of its special properties and characteristics, 2205 dual-phase steel is widely used, and it is the most widely used brand in dual-phase steel so far.

*PREN value: %Cr+3.3x%Mo+ 16x%N

Three. Physical and mechanical properties of 2205(S3 1803, F5 1, 1.4462) duplex stainless steel;

1 and 2205(S3 1803, F5 1, 1.4462) density: 8.0g/cm3.

2.2205(S3 1803, F5 1, 1.4462) tensile strength of dual-phase steel: σ b ≥ 620mpa.

The yield strength of 3.2205(S3 1803, F5 1, 1.4462) dual-phase steel: σ0.2≥450Mpa.

4.2205 (S31803, F5 1, 1.4462) Elongation of dual-phase steel: δ≥25%.

Four. Corrosion resistance of 2205(S3 1803, F5 1, 1.4462) duplex stainless steel;

1, uniform corrosion: due to the chromium content (22%), molybdenum content (3%) and nitrogen content (0. 18%) of 2205 dual-phase steel, the corrosion resistance of 2205 is better than that of 3 16L and 3 17L in most environments.

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

3. Stress corrosion resistance: The dual-phase structure of 2205 dual-phase steel is helpful to improve the stress corrosion cracking resistance of stainless steel. Under the action of certain temperature, strain, oxygen and chloride, chloride stress corrosion will occur in austenitic stainless steel. Because these conditions are not easy to control, the use of 304L, 3 16L, 3 17L is restricted in this respect.

4. Corrosion fatigue resistance: 2205 dual-phase steel has high corrosion fatigue strength due to its high strength and corrosion resistance. Processing equipment is easily affected by corrosive environment and loading cycle, and the characteristics of 2205 are very suitable for this kind of application.

Verb (abbreviation of verb) 2205(S3 1803, F5 1, 1.4462) Duplex stainless steel structure:

2205(S3 1803, F5 1, 1.4462) dual-phase steel in1900/1922f (1040//kloc-0). If the heat treatment temperature is higher than 2000°F, the ferrite composition may increase. Like other duplex stainless steels, 2205 duplex steel is easily affected by intermetallic phase precipitation. Intermetallic phase precipitates between1300 f-1800 f, and1600 f has the fastest precipitation speed, so it is necessary to test 2205 to ensure that there is no intermetallic phase. Refer to ASTM-A923 for the test.

Machinability of 6.2205(S3 1803, F5 1, 1.4462) duplex stainless steel;

1. Hot forming: We suggest that the forming should be carried out below 600°F as far as possible. During hot forming, the whole workpiece should be heated, and the temperature range is1750 F to 2250 F. At this temperature, 2205 dual-phase steel is very soft. If the temperature is too high, 2205 dual-phase steel is prone to hot cracking. If it is lower than this temperature, austenite will break. When the temperature is lower than 1700 F, the intermetallic phase forms rapidly due to the influence of temperature and deformation. Immediately after hot forming, solution annealing and quenching should be carried out at the lowest temperature of1900 f to restore its phase equilibrium, toughness and corrosion resistance. We don't recommend stress relief, but if necessary, the material should be solution annealed at the lowest temperature of 1900 F, then cooled quickly and quenched with water.

2. Cold forming: 2205 dual-phase steel can be cut and cold formed. However, 2205 dual-phase steel needs cold forming more than austenitic steel because of its high strength and hardness, and the springback factor should be fully considered because of its high strength.

3. Heat treatment: 2205 dual-phase steel should be annealed at the lowest temperature of 1900 F, then rapidly cooled and water quenched. This treatment is applied to solution annealing and stress relief. If the stress relief treatment is carried out at a temperature lower than1900 F, it will easily lead to the precipitation of harmful metal or nonmetal phases.

4. Machinability: On the high-speed machine tool, the feed speed and cutting speed of 2205 dual-phase steel are the same as 3 16L. If carbonized knives are used, the cutting speed will be reduced by about 20% compared with 3 16L, and the performance of machinery and its components plays a key role here.

5. Welding: 2205 alloy has good weldability. The performance of 2205 dual-phase steel is that the welded metal and thermal degradation parts still maintain the same corrosion resistance, strength and toughness as the base metal. It is not difficult to weld 2205 dual-phase steel, but it is necessary to design its welding program to keep a good phase balance after welding and avoid the precipitation of harmful metallic or nonmetallic phases.

VII. Application of 2205(S3 1803, F5 1, 1.4462) Duplex Stainless Steel:

Application fields of 2205 dual-phase steel: neutral chloride environment, oil refining industry, petrochemical industry, chemical pipeline, oil and gas industry, pulp and paper industry, chemical fertilizer industry, urea industry, phosphate fertilizer industry, seawater environment, energy and environmental protection industry, light food industry, equipment for food and pharmaceutical industry, high-strength structural parts, submarine pipeline, flue gas desulfurization, osmotic desalination equipment, sulfuric acid plant, ocean.

8. Varieties, specifications and supply status of 2205(S3 1803, F5 1, 1.4462) duplex stainless steel:

1. Shanghai Bing Zheng industrial product classification: 2205 seamless pipe, 2205 steel plate, 2205 round steel, 2205 forging, 2205 flange, 2205 circular ring, 2205 welded pipe, 2205 steel strip, 2205 wire rod and 2205 matching welding materials.

2, delivery status: seamless pipe: solid solution+acid white, the length can be determined; Plate: solid solution, pickling and trimming; Welded pipe: solid solution acid white +RT% flaw detection, forging: annealing+turning; Bar forging and rolling, surface polishing or turning; The strip is output after cold rolling, solution softening and descaling; The wire is delivered in the state of solution pickling, disc shape or straight bar, and the solution straight bar is finely polished.