Super Duplex S31803 Steel Plate

Grades Duplex 1.4462 - UNS S31803 - F51 Sheet/ Plate
Thickness 3 mm - 100 mm
Width 1000 / 1250 / 1500 / 2000 / 2500 mm
Length 2000 / 2500 / 3000 / 6000 / 6000 tot max. 8000 mm

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Product Introduction

S31803 is a duplex stainless steel with excellent chemical balance, conforming to ASTM A240/A240M standards. "Duplex" refers to its microstructure consisting of approximately 50% austenite (γ phase) and 50% ferrite (α phase). HT PIPE is a astm sa240 uns s31803 sheet supplier with 15+ export experience. Contact us for more information and quotes for free!

ASTM A240 S31803 Duplex Steel Plate Specifications

Specifications	ASTM A240 , ASME SA240
Thickness	0.3mm-50mm
Sizes	1000 mm x 2000 mm, 1000 mm x 2000 mm, 122 0 mm x 2440 mm, 1250mm x 2500mm, 1500mm x 3000mm to 6000mm, 2000mm x 4000mm to 6000mm, 1500 mm x 3000 mm, 2000 mm x 2000 mm, 2000 mm x 4000 mm, 2m, 2.44m, 3m, 36" X 120" or 48" X 144", 4' x 8', Cut to size available
Surface	BA, 2B, 2D, NO.1, NO.4, NO.8, 8K, checkered, sandblast, brush, mirror, embossed, hairline, etching, etc
MOQ	No Minimum Order Quantity
Test Report	Raw material certificate 100% radiographic inspection report Third-party inspection report, etc. PED certificate
Supplied Forms	Fittings, Flanges Pipe, Tube Plate, Sheet, Strip, Coil Round Bar
Sample	Provide free samples
Delivery time	5-35 days

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Duplex S31803 Chemical Composition

Cr	Chromium	22.0 - 23.0%
Ni	Nickel	4.5 - 6.5%
Mn	Manganese	2.0% max
Si	Silicon	1.0% max
P	Phosphorous	0.03% max
S	Sulfur	0.02% max
C	Carbon	0.03% max
N	Nitrogen	0.1 - 0.2%
Mo	Molybdenum	3.0 - 3.5%
Fe	Iron	Balance

Performance and Advantages of S31803 Plate

stainless steel s31803 steel plate High Strength and Good Toughness

Due to the presence of its ferrite phase, S31803 possesses high mechanical strength. Its room-temperature yield strength (σ0.2) is nearly twice that of common 304 or 316 austenitic stainless steels. This means that thinner plate can be used for the same design load, reducing weight and cost, which is crucial for the economic viability of large structures such as ships and storage tanks. At the same time, the austenite phase provides sufficient toughness and ductility, avoiding the brittleness risk associated with high-strength ferritic steels.

s31803 hot rolled sheet Outstanding Corrosion Resistance

Resistance to Pitting and Crevice Corrosion: Its pitting resistance equivalent value (PREN = %Cr + 3.3×%Mo + 16×%N) is typically greater than 34, significantly higher than that of 316L (~24-26), making it resistant to chloride-rich environments such as seawater and chemical wastewater.

Resistance to Stress Corrosion Cracking: This is one of its greatest advantages over austenitic stainless steels such as 304 and 316. Austenitic stainless steels are prone to brittle cracking in tensile stress environments containing chloride ions, while S31803 is extremely resistant to this.

Uniform Corrosion Resistance: It exhibits excellent corrosion resistance to a variety of inorganic and organic acids, as well as alkalis, and particularly outperforms 316L in media such as dilute sulfuric acid and formic acid.

Material Testing

Hardness Test
Chemical Analysis – Spectro Analysis
Positive Material Identification – PMI Testing
Flattening Test
Micro and MacroTest
Pitting Resistance Test
Flaring Test
Intergranular Corrosion (IGC) Test

astm s31803 sheet Fatigue Resistance

High strength results in a higher fatigue strength limit, extending its service life under cyclic loading conditions (such as ship decks and pressure vessels).

uns s31803 stainless steel plate Cost-Effectiveness

Although its price per unit weight is higher than that of 316L, its higher strength reduces material usage, making its overall cost more competitive in many applications. Its longer service life also reduces maintenance and replacement costs.

super duplex s31803 steel plate Cutting and Forming

Sheet steel can be cut using plasma, water jet, or laser cutting. Cold forming (e.g., bending and curling) is possible, but due to its high strength and high work hardening rate, it requires greater forming forces than austenitic stainless steels and incurs greater tool wear. Avoid extremely tight bend radii.

Typical Applications of s31803 plate

Chemical and Petrochemical: Acetic, sulfuric, and phosphoric acid plants, cracked gas quenching systems in ethylene plants, and organic synthesis processes containing chlorides.
Marine Engineering and Seawater Desalination: Seawater cooling piping systems, preheaters, pumps, and piping in seawater desalination plants, and high-pressure seawater systems on ships.
Flue Gas Desulfurization (FGD) Systems: Wet areas most susceptible to corrosion, such as the absorber spray layer, demister, and outlet flue.
Paper Industry: Equipment and piping in the pulp bleaching process (ClO₂ environment).
Pharmaceutical and Food Industries: Demanding process steps requiring extreme cleanliness and corrosion resistance.
Environmental Protection: Wastewater treatment, particularly for industrial wastewater containing high levels of chlorides, sulfides, or acidic components.