Stainless steel pipe S31803

S31803 dual phase stainless steel is composed of 21% chromium, 2.5% molybdenum and nickel nitrogen form 4.5% duplex stainless steel alloy. It has high strength, good toughness and good overall and local stress corrosion resistance. The yield strength of S31803 duplex stainless steel is two times that of austenitic stainless steel, this feature enables designers to reduce weight in the design of products, let this alloy has a price advantage than 316317L. This alloy is particularly applicable to -50 degrees F/+600 degrees F temperature range. Beyond this temperature range of applications, also can consider this kind of alloy, but there are some limitations, especially when used in welding structure.

The characteristics of S31803 duplex stainless steel:

1.S31803 dual phase stainless steel and austenitic stainless steel 316L and 317L compared, S31803 properties of dual phase steel in the resistance to pitting and crevice corrosion is more superior, it has very high corrosion resistance of austenite, and compared, its lower thermal expansion coefficient, high thermal conductivity.

2.S31803 dual phase stainless steel and austenitic stainless steel are compared, the compressive strength is two times, compared with 316L and 317L, the designer can reduce the weight. Alloy 2205 is particularly applicable to - 50 degrees F/+600 degrees F temperature range, in a strictly limited circumstances (especially for welding structure), can also be used to lower the temperature.

Chemical composition: C = 0.030, Mn = 2 Si = 1, P = 0.030 S = 0.020 Cr and 22 ~ 23 Ni and 4.5 ~ 6.5 Mo3.0 ~ 3.5 N0.14 ~ 0.20 (austenite and ferrite)

S31803 dual phase stainless steel applications:

Pressure vessels, pressure tanks, high pressure pipe, heat exchanger (chemical processing industry).

Petroleum natural gas pipeline, the heat exchanger tubes.

And the sewage treatment system.

And the pulp and paper industry classifier, bleaching equipment, storage and processing system.

High strength corrosion environment of the rotary shaft, impeller blades, press roller, etc..

Cargo tank, ship or truck

And food processing equipment

S31803 dual phase stainless steel standard:

ASTM/ASME..A240 UNS S32205/S31803...

EURONORM..1.4462 X2CrNiMoN 22.5.3...

AFNOR....Z3 CrNi 22.05 AZ

DIN....W. Nr 1.4462

S31803 dual phase stainless steel corrosion resistance:

Uniform corrosion

Because the chromium content (22%), Mo (3%) and nitrogen content (0.18%), 2205 of the properties of corrosion resistance is better than that of 316L and 317L in most environments.

Local corrosion

The content of chromium, molybdenum and nitrogen S31803 duplex stainless steel in the oxidizing and acidic solution, has a strong ability to resist corrosion and crevice corrosion.

Stress corrosion resistance

Dual phase microstructure of stainless steel is helpful to improve the resistance of the stainless steel stress corrosion cracking ability. At a certain temperature, oxygen tension exists, and the absence of chloride, austenitic stainless steel will happen to chloride stress corrosion. Because of these conditions is not easy to control, so the use of 304L, 316L and 317L are limited in this respect.

Corrosion fatigue

High strength and corrosion resistance of S31803 duplex stainless steel which has high resistance to corrosion fatigue strength. Processing equipment susceptible to corrosion environment and cyclic loading, the characteristics of S31803 duplex stainless steel is very suitable for such applications.

Structure

Chemical composition of S31803 duplex stainless steel after 1900 degrees /1922 degrees F (1040 degrees /1080 degrees C) solution annealed microstructure can obtain ideal 50 alpha / 50 gamma. If the heat treatment temperatures above 2000 degrees F, may lead to an increase in the ferrite components. Like other dual phase stainless steel, alloy 2205 is easily affected by the intermetallic phase precipitation. Intermetallic phases at 1300 DEG F and 1800 DEG between F at 1600 DEG F precipitation, temperature, the precipitation of the fastest. Therefore, we need to conduct experiments on the S31803 duplex stainless steel, to ensure that no intermetallic phase, testing, reference ASTM A 923.

S31803 dual phase stainless steel processing

Hot forming

We suggest that should be carried out in the following 600 degrees F temperature forming. In hot forming processing, the workpiece should be heated, should be in 1750 degrees F to 2250 degrees F within the temperature range of 2205 alloy under this temperature, very soft. If the temperature is too high, easy to hot tearing 2205 alloy. Below this temperature, the austenite will be broken. Below 1700 degrees F, because of the influence of temperature and deformation, intermetallic will soon form. After hot forming, should be an immediate solution annealed to at least 1900 degrees F temperature, and quenching to restore its phase equilibrium, toughness and corrosion resistance. We do not recommend eliminating stress, but if you must do so, materials to be solution annealed at a minimum of 1900 degrees F temperatures, then rapidly cooling, water quenching.

Cold forming

S31803 dual phase stainless steel can be cut and cold forming. However, due to the high strength and hardness of 2205 alloy itself, it than austenitic steel is more need for cold forming, also because of its high strength, should give full consideration to the factors of springback.