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Utilizing 26 high-precision cold rolling mills and 6 cold drawing machines, we ensure dimensional accuracy and superior mechanical properties.
904L Severe Corrosion Resistant Tubing
Super Austenitic | UNS N08904 | Copper-Enhanced Acid Resistance
ASTM B677/B673 | High-Alloy CertifiedRelated Products
Introduction
904L Severe Corrosion Resistant Tubing is a super-austenitic alloy that steps well beyond the standard 300-series chemistry, combining 23-28% nickel, 19-23% chromium, 4.0-5.0% molybdenum, and a distinctive 1.0-2.0% copper addition that the 316 and 317 families do not include. That copper content is the key differentiator: it specifically improves resistance to reducing acids such as dilute sulfuric acid and phosphoric acid, environments where molybdenum alone provides only partial protection. Carbon is held below 0.02% as standard practice for this grade, keeping intergranular corrosion resistance high even after multiple weld passes on thicker sections.
The high nickel content also gives 904L excellent resistance to chloride stress corrosion cracking, a failure mode that limits standard austenitic grades in hot chloride environments even when pitting resistance alone would seem adequate. This combination of acid resistance and chloride SCC resistance makes 904L a practical alternative to duplex stainless in applications where the process chemistry specifically favors nickel-based passivation — such as sulfuric acid pickling lines — rather than the higher-strength, lower-nickel profile that duplex grades offer. It is worth noting that 904L's pitting resistance equivalent, while excellent among austenitic grades, is generally below that of superduplex alloys; selection between the two should be based on the specific acid chemistry rather than chloride content alone.
Common installations include sulfuric acid pickling and descaling equipment, phosphoric acid fertilizer production piping, flue gas desulfurization systems handling concentrated chloride condensate, and seawater-cooled heat exchangers in chemical plants where both acid resistance and chloride tolerance are required simultaneously. Because raw material and processing costs run well above standard austenitic grades, 904L is typically specified only after 316L and 317L have been evaluated and found insufficient for the specific corrosive duty.
Specifications
| Material Grade | 904L (UNS N08904) |
| Standard | ASTM B677 (pipe), B673/B674 (tube) |
| Outer Diameter | 9.5mm - 168.3mm |
| Wall Thickness | 1.0mm - 12mm |
| Length | Up to 12000mm |
| Finish | Solution Annealed, Pickled |
Chemical Composition
| C | Cr | Ni | Mo | Cu |
| ≤.02 | 19-23 | 23-28 | 4.0-5.0 | 1.0-2.0 |
Cu Enhanced Acid Resistant
Mechanical Strength
Comprehensive Info
| MOQ | 500kg |
| Lead Time | 35 - 50 Days |
| Testing | 100% ET/UT & Hydro-test |
| Raw Material | VIM/VOD High-Purity Melt |
Key Applications
Acid Pickling Sulfuric acid pickling and descaling equipment
Fertilizer Production Phosphoric acid process piping
Seawater Cooling Chloride-tolerant chemical plant exchangers
Advantages
Copper Enhanced
Copper addition specifically improves reducing-acid resistance.
Chloride SCC Resistant
High nickel content resists chloride stress corrosion cracking.
Broad Acid Range
Performs across sulfuric, phosphoric, and mixed acid duties.
Field Proven
Long service history in fertilizer and pickling industries.
About Jiangsu Jend Tube Co.,Ltd.
As China 904L Severe Corrosion Resistant Tubing Manufacturers and Wholesale 904L Severe Corrosion Resistant Tubing Factory, Established in 2011 and is a manufacturing enterprise with a complete manufacturing cycle from raw material selection to finished product delivery. The company currently has more than 100 employees, covers an area of 30015 square meters, and has a registered capital of 48 million yuan, annual production capacity of 3800 tons.
The company has passed ISO9001:2015 quality certification, domestic pressure vessel TS certification, and foreign pressure vessel PED certification. With rich experience and mature technology, we have been expanding our market internationally. At present, our products are exported to more than 50 countries and regions including Europe, America, Southeast Asia, and the Middle East.
The company adheres to different production norms and standards such as the American standard (ASTM), the European standard (EN), the German standard (DIN), the Japanese standard (JIS), the Russian standard (GOST), and the Chinese standard (GB).
Our company specializes in and customizes various specifications of Martensite TP410 (0Cr13, 1Cr13), Ferrite TP405 (1Cr13Al), TP430 (1Cr17), TP444 (0Cr18Mo2), TP439, TP409 (0Cr11Ti), It is also proficient in manufacturing Austenitic seamless stainless steel pipes of series such as TP304(L/H), TP316(L/H/Ti), TP310S, TP317, TP321(H) and TP347(H). Duplex such as S31803, S2205, S32750, S32304, and Nickel-based alloys Monel400, Monel600, Monel800, GH3030, 904L, Inconel 625, etc.
The company mainly produces seamless steel pipes with the following specifications: outer diameter: 3.18mm to 406.4mm, wall thickness: 0.3mm to 20mm, and the longest length is 25000mm. Additionally, it can customize seamless steel pipes with special materials and specifications according to customer requirements. The company attaches great importance to scientific innovation. The staff of the company vigorously develop technological research and development.
Jiangsu Jend Tube Co.,Ltd. will continuously accumulate professional knowledge and capabilities, striving to become a leader in the domestic market and even the world market. Strive to be the most reassuring pipe manufacturing enterprise for customers.
Precision Manufacturing and Process Optimization
We rely on precision equipment and optimized production technologies to achieve outstanding mechanical performance and consistent product quality.
Cold Rolling and Cold Drawing
Solution Heat Treatment
Natural gas solution treatment furnaces and BA solution treatment furnaces optimize the material's grain structure, enhancing corrosion resistance.
Precision Straightening and Polishing
10 straightening machines and 8 finishing polishing machines guarantee product surface smoothness and dimensional accuracy.
Automated Inspection and Quality Assurance
Real-time monitoring systems ensure the stable quality of every batch of products.
Usage Tips
Grade Selection
Compare 904L against duplex alloys based on specific acid chemistry, not chloride content alone — duplex may outperform in some services and underperform in others.
Welding Filler
Use matching high-nickel filler metal (such as ERNiCrMo-3) to preserve corrosion resistance across weld joints in acid service.
Services
100% ET/UT Inspection
Full-length testing for pressure-critical service.
Bevel & End Prep
Weld-ready ends for acid plant piping tie-ins.
Certified Documentation
Full traceability and NACE-compliant testing available.
Logistics
30% T/T Deposit / L/C at sight. Individually wrapped with VCI protection and end caps, packed in reinforced wooden crates for corrosive-service project sites.
Standards
ASTM B673/B674/B677
NACE MR0175 (on request)
ISO 9001
Frequently Asked Questions
What makes 904L different from 316L or 317L?
904L adds copper and significantly higher nickel and molybdenum content, giving it much stronger resistance to reducing acids like dilute sulfuric and phosphoric acid than either 316L or 317L can offer.
Why is copper added to this alloy?
Copper specifically improves corrosion resistance in reducing acid environments, which molybdenum alone does not fully address.
Is 904L better than duplex stainless for chloride service?
It depends on the acid chemistry involved; 904L generally has a lower pitting resistance equivalent than superduplex, so selection should be based on the specific process fluid rather than chloride content alone.
What industries commonly use 904L?
Sulfuric acid pickling, phosphoric acid fertilizer production, and chloride-tolerant seawater cooling systems are the most common applications.
What welding filler metal is recommended?
A matching high-nickel filler such as ERNiCrMo-3 is commonly used to preserve corrosion resistance through the weld.
Why does 904L cost more than standard stainless grades?
The higher nickel, molybdenum, and copper content, combined with more demanding melting practices, increase both raw material and processing costs relative to 300-series grades.
Need 904L Tubing for a Severe Corrosion Application?
Send us your process fluid concentration and temperature for a corrosion-suitability assessment.
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