S32205 S31803 1.4462 Resistance to Corrosion

2205 duplex stainless steel is a cost effective solution for many applications where the 300 series stainless steels are susceptible to chloride stress corrosion cracking. Stress corrosion cracking occurs when stainless steels are subjected to tensile stress, while in contact with solutions containing chlorides. Increasing temperatures also increase the susceptibility of stainless steels to stress corrosion cracking.

The combination of chromium, molybdenum and nitrogen convey the good resistance of 2205 to chloride pitting and crevice corrosion. This resistance is extremely important for services such as marine environments, brackish water, bleaching operations, closed loop water systems and some food processing applications. The high chromium, molybdenum and nitrogen contents of 2205 provide corrosion resistance superior to common stainless steels, such as, 316L and 317L in most environments.

General Corrosion
Because of its high chromium (22%), molybdenum (3%), and nitrogen (0.18%) contents, the corrosion resistance properties of 2205 are superior to that of 316L or 317L in most environments.

Localized Corrosion Resistance
The chromium, molybdenum, and nitrogen in 2205 also provide excellent resistance to pitting and crevice corrosion even in very oxidizing and acidic solutions.

Isocorrosion Curves 4 mpy (0.1 mm/yr), in sulfuric
acid solution containing 2000 ppm

Stress Corrosion Resistance
The duplex microstructure is known to improve the stress corrosion cracking resistance of stainless steels.

Chloride stress corrosion cracking of austenitic stainless steels can occur when the necessary conditions of temperature, tensile stress, oxygen, and chlorides are present. Since these conditions are not easily controlled, stress corrosion cracking has often been a barrier to utilizing 304L, 316L, or 317L.

Corrosion Fatigue Resistence
Alloy 2205 combines high strength and high corrosion resistance to produce high corrosion fatigue strength. Applications in which processing equipment is subject to both an aggresively corrosive enviroment and to cycle loading can benefit from the properties of 2205.

Critical Pitting Temperature in 1M NaCl Measured
Using the AvestaPolarit Pitting Cell

Critical Crevice Corrosion Temperature (CCT)
in 10% FeCl3•6H2O

General Corrosion in Wet Process Phosphoric Acids

Stress Corrosion Cracking Resistance

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S31803 Stainless Steel Pipe