Duplex Stainless Plate

 Duplex Stainless Plate PDF file

Corrosion Resistance Plus High Strength

Sandmeyer Steel has an extensive inventory of Duplex LDX 2101^®, 2304, 2205, and 2507 plate products available to satisfy your requirements.

General Characteristics
Duplex Stainless Steels combine many of the beneficial properties of ferritic and austenitic materials to provide both high strength and good corrosion resistance. Due to their high chromium, molybdenum and nitrogen contents and duplex structure, these steels offer many benefits in comparison to 300 series austenitic grades:
• High Strength - Approximately twice the level of austenitics
• Good resistance to pitting and crevice corrosion
• Excellent resistance to stress corrosion cracking
• Good erosion and fatigue resistance
• Good weldability and increased heat transfer
• More stable pricing due to lower Ni levels than
  austenitic stainless

Applications
Due to these high strength and corrosion resistance properties, duplex stainless steels are used in a variety of applications such as:
• Pressure vessels, reactor tanks, and heat exchangers
• Desalination plants and seawater systems
• Water transmission pipes
• Rotors, impellers, and shafts in industrial equipment
• Digesters, storage and clarifier tanks, stock washers,
  and other equipment for the pulp and paper industry
• Absorber towers, FGD systems in pollution control
• Phosphoric acid production
• Food, oil and gas, mining, and architectural
  applications
• Biofuels plants

Value Added Processing
The Value Added Plate Processing capabilities that have serviced
thousands of our satisfied customers for over 50 years are also available for your Plate Product requirements in Duplex Stainless Steels. With over 100 pieces of in-house plate processing equipment, Sandmeyer can provide you with nearly any shape or configuration required. From plasma cut edge beveling to band saw cutting to abrasive waterjet cutting to Machincut rings and discs to rolled and code-welded rings, Sandmeyer’s value added plate processing capabilities are second to none.

Design Stress Allowance
One of the advantages of nitrogen-enriched duplex stainless steels is their higher strength levels in comparison to conventional austenitic stainless steels. This allows for construction of units in thinner cross-sections. This weight savings can dramatically reduce the material and fabrication cost of a vessel.

Corrosion Properties
Duplex stainless steels provide a wide range of corrosion resistance across a broad spectrum of applications. Below is a brief description of their resistance in various process environments.

General Corrosion
General corrosion is characterized as a uniform attack on a surface in contact with a corrosive medium. The corrosion resistance is considered good if the corrosion rate is less than 0.1 mm/yr. Because of their high chromium content, duplex stainless steels offer excellent corrosion resistance in many process environments. LDX 2101 has, in most cases, better resistance than 304L and in some applications resistance comparable to 316L. 2304, in most cases, is equivalent to 316L., while 2205 and 2507 exhibit even better resistance than most conventional austenitic stainless steels.

Sulfuric Acid
The isocorrosion diagram for sulfuric acid is shown to the right. In sulfuric acid contaminated by chloride ions, 2205 shows much better resistance than 316L and has similar resistance to 904L.

Isocorosion curves, 0.1 mm/year, in sulfuric acid

Hydrochloric Acid
304L and 316L have very limited use in hydrochloric acid due to the risk of general and localized corrosion. 2507, and to some extent 2205, can be used in dilute hydrochloric acid.

Nitric Acid
In strongly oxidizing acids, e.g. nitric acid, non-molybdenum alloys are often more resistant. LDX 2101 and 2304 are good alternatives because of their high chromium and low molybdenum content.

Crevice Corrosion Resistance
The Critical Crevice Corrosion Temperature (CCCT) test is often used to compare the crevice corrosion resistance of various alloys.

Typical critical crevice corrosion temperature according to ASTM G48 Method F in 6%FeCl₃ + 1%HCl

Chloride Pitting Resistance
The pitting resistance of stainless steel can be related directly to alloy composition, where chromium, molybdenum and nitrogen are a weight %. The Pitting Resistance Equivalent Number (PREN) uses the following formula – the higher the number the better the pitting resistance – PREN = %Cr + 3.3Mo + 30N

PREN values for different austenitic and duplex grades

Alloy	200°F
304L	18
316L	24
LDX 2101	26
2304	26
904L	34
2205	35
254 SMO*	43
2507	43

Stress-Corrosion Cracking Resistance
Austenitic stainless steels can be attacked by chloride stress-corrosion cracking at elevated temperatures. Duplex stainless steels are less susceptible to this form of corrosion. The results
of a drop evaporation test indicate that duplex stainless steels are superior to conventional austenitic stainless steels.

Applied stress at rupture in % of Rp0.2 at 392°F

Fig. 7. Typical threshold stresses determined using the drop
evaporation test.

Duplex Press Release
LDX 2101 Spec Sheet
2304 Spec Sheet
2205 Spec Sheet
2507 Spec Sheet

Produt Information:
E-Z Drill Plate
Vacuum Select Plate
Stainless Steel Round Bar
High Performance
  Nickel Alloys
Hub-Less Plate Flanges
Wide Plate
Duplex Stainless Plate

Value Added Processes:
Plasma Cutting
Abrasive Waterjet Cutting
Machincut
Saw Cut
Drilling, Tapping,
  Counterboring
Milling
Polishing
Flattening
Rolled & Welded Rings