S32750 super duplex stainless steel (UNS S32750, also known as SAF 2507, 1.4410, F53, 022Cr25Ni7Mo4N) 

has ultra-high strength and excellent corrosion resistance, and is widely used in multiple fields. ‌

Application area

Marine Engineering: S32750 is widely used in marine engineering equipment such as seawater desalination equipment, submarine pipelines, propeller shafts, etc. Due to its excellent corrosion resistance and high strength, it is particularly suitable for high salt spray environments

Chemical and petrochemical industries: In chemical equipment such as flue gas desulfurization systems (FGDs), acid oil and gas pipelines, and phosphoric acid reactors, S32750 performs well and can withstand high concentrations of sulfuric acid, phosphoric acid, and wet process media

Energy and Environmental Protection: S32750 is an ideal choice for energy and environmental protection equipment such as nuclear power plant condensers, sewage treatment equipment, incinerators, etc. due to its corrosion resistance and high temperature performance

Lightweight Replacement: S32750 can replace materials such as 316L and 2205, reducing equipment thickness and cost, especially in applications that require lightweight performance

Chemical composition and performance characteristics

S32750 is an austenitic ferritic duplex stainless steel with a PREN value ≥ 41, 

which combines high strength and corrosion resistance. 

1.Its main chemical components include 

chromium (Cr) 24-26%, nickel (Ni) 6-8%, molybdenum (Mo) 3-5%, nitrogen (N) 0.24-0.32%, etc.

 Its tensile strength is ≥ 795-1000 MPa, yield strength is ≥ 550 MPa, elongation is ≥ 15%, and hardness is ≤ 227 HBW

2. In addition, S32750 performs well at low temperatures and can maintain an impact energy of ≥ 50 J at -50 ℃

Key points of processing and welding

The processing and welding of S32750 require special attention to the following points:

Heat treatment: The solution treatment temperature is 1020-1100 ℃, and rapid water quenching is used to optimize the biphasic ratio; After forging, it is necessary to immediately cool it with water to avoid the precipitation of brittle phases

Welding: It is recommended to use ER2594 or ERNiCrMo-3 welding materials with interlayer temperature ≤ 100 ℃. No heat treatment is required after welding, but carbon steel contamination should be avoided

Forming processing: The forging temperature is 1000-1180 ℃, and the final forging temperature needs to be controlled between 800-900 ℃

Other similar duplex stainless steel material 

According to its application , some popular grades are as following:

Delivery condition:

1. Forged + annealing + black surface

2. Forged + annealing + turning  

3. Forged + solution + black surface

4. Forged + solution + turning