904L stainless steel (UNS N08904) is a super-austenitic stainless steel with high molybdenum, nickel, and copper content. It is designed for maximum resistance to severe corrosion, particularly against sulfuric acid and chloride attack. The addition of copper (Cu) significantly enhances its resistance to reducing acids, making it the material of choice for the chemical processing, fertilizer, and offshore industries. It is designated as 015Cr21Ni26Mo5Cu2 (GB/T, China), SUS890L (JIS, Japan), and 1.4539 (EN, Europe).
Chemical Composition
Typical chemical composition (% by mass) per ASTM B625 / EN 10088.
| Grade | C (%) | Cr (%) | Ni (%) | Mo (%) | Cu (%) |
|---|---|---|---|---|---|
| 904L / N08904 | ≤0.02 | 19.0–23.0 | 23.0–28.0 | 4.0–5.0 | 1.0–2.0 |
Note: The high Nickel (Ni) content provides resistance to stress corrosion cracking, while the addition of Copper (Cu) gives it exceptional resistance to sulfuric acid environments.
Mechanical Properties
| Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|
| 904L | ≥220 | ≥490 | ≥35 | ≤150 |
Available Sizes & Delivery
| Thickness (Plate/Sheet) | 0.5–100 mm |
| Diameter (Round Bar) | 10–300 mm |
| Forms Available | Plate, sheet, round bar, seamless/welded pipe, fitting |
| Standard | ASTM B625 / ASTM A240 / EN 10088 |
| Mill Test Certificate | EN 10204 3.1 with every shipment |
| MOQ | 1 Ton (Premium material) |
| Delivery Time | Within 15-20 days (≤500 tons) |
Why Order from Zhongtang Steel?
- Ultimate Corrosion Resistance — Designed for the most aggressive chemical environments
- High Nickel & Molybdenum — Superior performance against pitting, crevice, and stress corrosion cracking
- EN 10204 3.1 MTC supplied with every shipment
- ISO 9001 certified manufacturer since 1998
- Mill-direct pricing — no trading company markup
Applications
- Chemical processing — reactors, heat exchangers handling sulfuric acid
- Fertilizer and pesticide production equipment
- Oil and gas — offshore platforms, sour gas pipelines
- Pharmaceutical industry equipment
- Pulp and paper bleaching systems
- Seawater cooling systems and desalination plants

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