904L Stainless Steel: The Tough and Corrosion-Resistant Metal of Choice

Duplex 904L is a high-alloy austenitic stainless steel that offers excellent corrosion resistance in a wide range of environments. The alloy consists of chromium, nickel, molybdenum, and nitrogen, which give it superior resistance to stress corrosion cracking, crevice corrosion, pitting, and general corrosion.

In this article, we will discuss the various forms of Duplex 904L available in the market, their chemical composition, mechanical properties, applications, standards, and ASTM equivalents. We will also explore the difference between Duplex 904L and 316L and talk about our experience with the alloy.

Forms of Duplex 904L:

Duplex 904L is available in various forms, including pipe, tube, coiled tube, sheet, coil, round bar, and plate. Let’s take a closer look at each of these forms.

1. Pipe and Tube: Duplex 904L pipes and tubes are widely used in the oil and gas industry due to their excellent corrosion resistance. They can withstand high temperatures and pressures and are resistant to chloride-induced stress corrosion cracking. These pipes and tubes are available in various sizes and thicknesses to suit different application requirements.
2. Coiled Tube: Duplex 904L coiled tubes are used in heat exchangers and other applications where space is limited. These tubes offer superior resistance to corrosion and are available in various sizes and thicknesses.
3. Sheet and Coil: Duplex 904L sheets and coils are used in various industries, including chemical processing, petrochemicals, and food processing. These sheets and coils offer excellent resistance to corrosion and can be easily fabricated.
4. Round Bar: Duplex 904L round bars are used in various applications, including pumps, valves, and other components that require high strength and corrosion resistance. These round bars are available in various sizes and lengths to suit different application requirements.
5. Plate: Duplex 904L plates are used in various industries, including chemical processing, oil and gas, and pulp and paper. These plates offer excellent resistance to corrosion and can be easily welded and fabricated.

Chemical Composition of Duplex 904L:

The chemical composition of Duplex 904L is as follows:

• Chromium: 19.0 – 23.0%
• Nickel: 24.0 – 26.0%
• Molybdenum: 4.0 – 5.0%
• Nitrogen: 0.10 – 0.22%
• Carbon: 0.02% max
• Manganese: 2.0% max
• Silicon: 1.0% max
• Phosphorus: 0.03% max
• Sulfur: 0.01% max

Mechanical Properties of Duplex 904L:

The mechanical properties of Duplex 904L at room temperature are as follows:

• Density: 7.95 g/cm3
• Tensile strength: 490 MPa (71 ksi)
• Yield strength: 220 MPa (32 ksi)
• Elongation: 35%
• Hardness: Brinell 190, Rockwell B90

Applications of Duplex 904L:

Duplex 904L has a wide range of applications in various industries, including:

• Oil and gas industry: pipes, tubes, and components for offshore platforms, pipelines, and refineries.
• Chemical processing: tanks, vessels, and valves for handling corrosive chemicals.
• Pulp and paper: digester tanks and bleach washers.
• Food processing: equipment for handling acidic foods and beverages.
• Pharmaceuticals: process equipment for manufacturing drugs and medicines.

Standards and ASTM Equivalents:

Duplex 904L is available in various standards and ASTM equivalents, including:

• ASTM A240/A240M: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications.
• ASTM A276/A276M: Standard Specification for Stainless Steel Bars and Shapes.
• ASTM A312/A312M: Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes.
• EN 1.4539 (X1NiCrMoCu25-20-5): European standard for Duplex 904L.

Difference Between Duplex 904L and 316L:

Duplex 904L and 316L are both austenitic stainless steels, but they differ in their chemical compositions and properties. Let’s take a look at some of the differences between the two alloys.

• Chemical Composition: Duplex 904L contains higher levels of chromium, nickel, and molybdenum than 316L, which gives it superior resistance to corrosion.
• Mechanical Properties: Duplex 904L has higher tensile and yield strength than 316L, which makes it a stronger and more durable alloy. Duplex 904L also has better corrosion resistance, especially in harsh environments that contain chlorides or acids.
• Price: Duplex 904L is generally more expensive than 316L due to its higher alloy content and superior properties. However, the cost may be justified in applications where corrosion resistance and strength are critical factors.
• Weldability: Both alloys are weldable, but Duplex 904L may require more care during welding due to its higher alloy content. Preheating and post-weld heat treatment may be necessary to avoid cracking and ensure proper corrosion resistance.Experience with Duplex 904L:At ANTON METAL, we have over 20 years of experience working with Duplex 904L and other high-performance alloys. Our team of experts can help you choose the right alloy for your application and provide custom solutions to meet your specific requirements.We offer a wide range of Duplex 904L products, including pipes, tubes, sheets, coils, plates, and round bars, in various sizes and thicknesses. We can also provide custom fabrication services, including cutting, bending, welding, and machining, to meet your exact specifications.Conclusion:Duplex 904L is a high-alloy austenitic stainless steel that offers excellent corrosion resistance, strength, and durability in various harsh environments. It is available in various forms, including pipe, tube, coiled tube, sheet, coil, round bar, and plate, and conforms to various standards and ASTM equivalents.Compared to 316L, Duplex 904L has higher levels of chromium, nickel, and molybdenum, which make it a stronger and more corrosion-resistant alloy. However, it may be more expensive and require more care during welding.

  At ANTON METAL, we have extensive experience working with Duplex 904L and other high-performance alloys. Contact us today to learn more about our products and services and how we can help you choose the right alloy for your application.