Super austenitic stainless steel 904L is an ultra-low carbon steel with high chromium, nickel, and molybdenum-containing copper. It has good corrosion resistance, especially in phosphoric acid and sulfuric acid environments, and has excellent overall corrosion resistance. Compared with austenitic 304 stainless steel and 316L stainless steel, it has better anti-pitting and crevice corrosion, intergranular corrosion, stress corrosion cracking, and general corrosion resistance.
Therefore, it is widely used in sewage treatment, chemical, paper, and other manufacturing industries. As my country’s current chemical and other equipment manufacturing industries urgently need steel materials, it has been monopolized by foreign coauntries, and domestic manufacturers can only rely on high-priced imports.
In April 2008, TISCO successfully developed the first 904L plate in China, with various performance indicators reaching the level of imported products. Its successful development and market recognition have made TISCO the first domestic manufacturer of mass production of super austenitic stainless steel 904L medium and heavy plates, and it has also made TISCO the only domestic manufacturer that can simultaneously produce super austenitic, super duplex, and super iron. Manufacturer of ferrite and super martensitic stainless steel.
904L Stainless Steel Plate
According to the relevant person in charge of the marketing department of Taiyuan Iron and Steel, after extensive market research, super austenitic stainless steel 904L was listed as a key development product of Taiyuan Iron and Steel in 2007. In August of the same year, Taiyuan Iron and Steel set up a special national steel product development group in short supply, and the technical center established a super austenitic stainless steel development group to tackle key problems. In April 2008, mass production started. By the end of this year, the 904L cold-rolled sheet is expected to be trial-produced.
Core Technical Parameters: An In-Depth Analysis of 904L Performance
Understanding the technical parameters of 904L stainless steel helps us more comprehensively assess its suitability. Below are its key chemical composition and mechanical properties:
904L Chemical Composition
Grade | C | Mn | P | S | Si | Ni | Cr | Mo | Cu |
904L | ≤0.02 | ≤2.00 | ≤0.045 | ≤0.035 | ≤1.0 | 23.0-28.0 | 19.0-23.0 | 4.0-5.0 | 1.0-2.0 |
904L Mechanical Properties
Distinguish | YS（MPa） | TS（MPa） | EL | HRB |
Standard | ≥216 | ≥490 | ≥35 | ≤90 |
Actual | 340 | 624 | 46 | 175（Hv） |
① Like other commonly used Cr-Ni austenitic steels, it has good cold and hot workability;
② The maximum heating temperature during hot forging can reach 1180 degrees Celsius, and the minimum forging stop temperature is not less than 900 degrees Celsius. The hot forming of this steel can be carried out at 1000-1150 degrees Celsius. The heat treatment process of the steel is 1100–1150 degrees Celsius, and it is quickly cooled after heating.
904L Welding Performance:
904L stainless steel can be welded using general techniques, but manual arc welding and argon tungsten arc welding are preferred:
For plates ≤6 mm, electrode diameter ≤2.5 mm.
For plates >6 mm, electrode diameter ≤3.2 mm.
Post-weld heat treatment can be conducted at 1075–1125°C, followed by rapid cooling.
When using argon tungsten arc welding, the filler metal should match the base material. Pickling and passivation are recommended after welding.
Corrosion Resistance
904L was specifically developed to resist sulfuric acid corrosion, and it also performs well in acetic acid, formic acid, phosphoric acid, and their mixed acids under normal pressures.
Intergranular Corrosion
Tests following GB1223-75 (T-method) indicate that even when carbon content reaches 0.038%, 904L stainless steel requires over 1 hour of sensitization to be vulnerable. Proper welding processes ensure that components ≤30 mm thick remain safe from intergranular corrosion.
Stress Corrosion Resistance of 904L Steel
| Grade | Test medium | Time for stress corrosion cracking, h |
| 00Cr18Ni10 | 40%CaCl2, Boiling temperature | <12 |
| 00Cr18Ni13Mo2 | Same as above | <12 |
| 904L | Same as above | 1000, No stress corrosion |
| 00Cr18Ni10 | 25%NaCl+1%K2Cr2O7,pH=5, boiling | <20 |
| 00Cr18Ni13Mo2 | Same as above | <321 |
| 904L | Same as above | 1000, No stress corrosion |
Applications of 904L Stainless Steel
Chemical Industry: Tanks, reactors, piping, and heat exchangers for strong acids.
Marine Engineering: Seawater cooling systems and offshore platforms.
Oil & Gas: Pipelines, storage tanks, and processing equipment exposed to chlorides and sulfates.
Pharmaceutical & Food Processing: Reactors, pipelines, and tanks requiring high hygiene standards and corrosion resistance.
For any project handling harsh, corrosive media, the right material selection is the cornerstone of success. 904L stainless steel, a proven material in both industrial and luxury sectors, offers a wealth of potential and value that deserves further exploration.
Our team of experts, with deep knowledge of materials science and extensive industry application experience, can provide expert consultation on 904L stainless steel and its processing. Whether you’re selecting materials for new chemical equipment or seeking a more reliable alternative for an existing production line, we can provide customized solutions tailored to your specific needs.
Please feel free to contact us to discuss how we can leverage the exceptional properties of 904L stainless steel to create long-term, sustainable value for your project.
Why Choose Huaxiao Metal for 904L Stainless Steel?
Because 904L presents high technical barriers in both production and processing, selecting a supplier requires extreme caution. A qualified 904L supplier is more than just a material handler; it must be a partner with expertise and in-depth processing capabilities.
First, the supplier should be able to provide qualified products that comply with international standards (such as UNS N08904 or EN 1.4539) and provide corresponding quality certifications and composition reports. Second, given the processing complexity of 904L, the ideal supplier should possess or be able to offer professional welding, heat treatment, and machining services. A supplier who can guide customers on proper welding techniques, or even provide customized welding solutions, can help them effectively avoid processing defects and ensure the material’s superior properties are fully realized in the final product.
Choosing a supplier with a strong technical background and comprehensive solutions is key to project success and maximizing long-term value. This is more than just a procurement exercise; it’s a strategic partnership.
As a leading Chinese stainless steel supplier, Huaxiao Metal provides:
Extensive Product Range: Cold-rolled, hot-rolled, polished, and color-treated 904L products.
Global Supply Network: Fast and reliable delivery worldwide.
Customization Services: Cutting, machining, and custom sizing to meet client specifications.
Contact Huaxiao Metal today to get a quote or learn more about custom 904L stainless steel solutions.
FAQ
What is 904L stainless steel?
904L is a super austenitic stainless steel with ultra-low carbon content and high levels of nickel, chromium, molybdenum, and copper. It offers excellent corrosion resistance, especially against sulfuric and phosphoric acids, and superior resistance to pitting, crevice corrosion, and stress corrosion cracking compared to 304 or 316L stainless steel.
What are the main applications of 904L stainless steel?
904L is widely used in chemical processing, marine engineering, oil and gas, pharmaceutical, and food industries. Common applications include tanks, reactors, piping, heat exchangers, seawater cooling systems, and high-hygiene equipment.
How does 904L compare to 304 and 316L stainless steel?
Compared to 304 and 316L, 904L has:
Higher resistance to pitting and crevice corrosion
Better stress corrosion cracking resistance
Improved durability in strong acid and chloride environments
While 904L is more expensive, its performance in harsh conditions justifies the cost.
Can 904L stainless steel be welded?
Yes, 904L can be welded using general methods, but manual arc welding and argon tungsten arc welding are preferred. Post-weld pickling and passivation are recommended. Plates ≤6 mm use electrodes ≤2.5 mm, while thicker plates require ≤3.2 mm electrodes.
What is the corrosion resistance of 904L?
904L is designed to resist sulfuric acid, acetic acid, formic acid, and phosphoric acid. It also exhibits excellent resistance to chloride-induced stress corrosion cracking, outperforming 304L and 316L in chloride-containing aqueous environments.
How to choose a reliable 904L stainless steel supplier?
Look for suppliers that offer:
Comprehensive product range (cold-rolled, hot-rolled, polished, and color-treated)
Global supply capability
Customization services for cutting, machining, and specific sizing
Huaxiao Metal is a trusted supplier meeting these criteria.
Is 904L suitable for long-term use in seawater?
Yes, 904L’s high nickel and molybdenum content makes it highly resistant to seawater corrosion, making it suitable for use in offshore platforms, seawater cooling systems, and marine pipelines.
In Conclusion:
904L stainless steel is a high-performance, super austenitic alloy ideal for chemical, marine, oil & gas, and pharmaceutical industries. Its excellent corrosion resistance, mechanical properties, and weldability make it superior to conventional 304 and 316L stainless steels. Choosing a reliable supplier like Huaxiao Metal ensures project success, reduced maintenance costs, and long-term performance.
Get in touch now for 904L stainless steel pricing and custom solutions!
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