Stainless Steel 904L Plate Information Encyclopedia
904L stainless steel plate is a high-alloy austenitic stainless steel known for its exceptional corrosion resistance, particularly in acidic environments and chloride solutions, due to its high nickel, chromium, molybdenum, and copper contents. Its advantages include excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SSC), as well as good toughness at low temperatures, excellent formability, and weldability. 904L plate is used in a wide range of applications, from chemical processing and pollution control equipment to offshore oil and gas platforms, heat exchangers, and specialized applications such as high-end watch cases.
What is the composition of 904L?
According to EN standards, this grade is designated as 1.4539 or X1NiCrMoCu25-20-5; according to UNS standards, it's designated as UNS S08904. 904L stainless steel contains extremely high levels of nickel, molybdenum, and chromium. The combination of these elements makes it extremely corrosion-resistant.
Chemical Composition of Stainless Steel 904L plates & sheets
| Element | Percentage (%) | Key Benefit Contribution |
| Nickel (Ni) | 23.0 – 28.0 | Stress Corrosion Cracking Resistance |
| Chromium (Cr) | 19.0 – 23.0 | General Corrosion & Oxidation Resistance |
| Molybdenum (Mo) | 4.0 – 5.0 | Pitting & Crevice Corrosion Resistance |
| Copper (Cu) | 1.0 – 2.0 | Resistance to Sulfuric Acid |
| Carbon (C) | ≤ 0.02 | Reduces Carbide Precipitation, Improves Weldability |
| Manganese (Mn) | ≤ 2.0 | Strength & Hot Workability |
| Silicon (Si) | ≤ 1.0 | Oxidation Resistance |
| Phosphorus (P) | ≤ 0.045 | (Controlled Impurity) |
| Sulfur (S) | ≤ 0.035 | (Controlled Impurity) |
| Iron (Fe) | Balance | Base Metal |
SS 904L plates & sheets Properties
| Property | Description |
| Exceptional Corrosion Resistance | Outstanding resistance to sulfuric, phosphoric, and acetic acids, plus chloride-rich environments |
| Robust Mechanical Strength | High tensile strength and toughness, maintaining structural integrity under stress |
| Excellent Weldability | Easily welded using standard fusion and resistance welding techniques |
| Good Formability | Allows for bending, pressing, and shaping without compromising material integrity |
| Reliable Temperature Resistance | Maintains strength and corrosion resistance at moderately elevated temperatures |
Applications of SS 904L Plates and Sheets
Chemical Plants: Heat exchangers, reaction vessels, piping, and condensers-basically, anywhere that handles difficult-to-corrode acidic materials-require it.
Marine Environments: It can be found in precision ship fittings, propeller shafts, seawater cooling systems, and critical components of desalination plants, which require resistance to seawater corrosion.
Pharmaceutical Industry: Maintaining the purity of materials is crucial in this industry, making 904L steel plate an ideal choice for process equipment, tanks, and piping due to its rust resistance.
Oil and Gas Industry: 904L plate is often used in demanding applications such as offshore platforms, piping, heat exchangers, and pressure vessels, particularly in corrosive hydrogen sulfide (H₂S) environments.
Gnee Steel specializes in the production and sale of a wide range of stainless steel products, including 304, 316, 321, 904, 904L, 2205 Duplex, 2205 Duplex, and 316L stainless steel. Gnee Steel's products are widely used in the kitchen, aerospace, chemical, power, automotive, and nuclear energy sectors. We also provide custom stainless steel solutions tailored to customer needs. For stainless steel pricing or custom alloy solutions, please email ru@gneesteelgroup.com for a quote.