Alloy 904L Tubing
Alloy 904L Tubing
Alloy 904L is a non-stabilized, high alloy austenitic stainless steel with low carbon content. It is widely used in applications where the corrosion properties of TP316/L and TP317/L are not adequate. The alloy also offers excellent formability, weldability, and toughness. The addition of copper gives alloy 904L corrosion resistant properties that are superior to the conventional chrome nickel stainless steels. Examples include resistance to sulfuric, phosphoric, and acetic acids.
Product Specifications
ASTM A213, A269 / ASME SA213 AVG wall / NACE MR0175, MR0103
Size Range
Outside Diameter (OD) | Wall Thickness |
.250”–1.000” | .035″–.065″ |
Cold finished and bright annealed tube.
Chemical Requirements
Alloy 904L (UNS N08904)
Composition %
C | Mn | P | S | Si | Cr Chromium | Ni Nickel | Mo | N | Cu |
0.020 max | 2.00 max | 0.040 max | 0.030 max | 1.00 max | 19.0–23.0 | 23.0–28.0 | 4.0–5.0 | 0.10 max | 1.00–2.00 |
Chemical Requirements
Alloy 904L (UNS N08904)
Composition %
C | Mn | P | S | Si | Cr | Ni | Mo | N | Cu |
0.020 max | 2.00 max | 0.040 max | 0.030 max | 1.00 max | 19.0–23.0 | 23.0–28.0 | 4.0–5.0 | 0.10 max | 1.00–2.00 |
Dimensional Tolerances
OD | OD Tolerance | Wall Tolerance |
≤ .500″ | ± .005” | ± 15% |
0.500”–1.500” | ± .005” | ± 10% |
Mechanical Properties
Yield Strength: | 31 ksi min |
Tensile Strength: | 71 ksi min |
Elongation (min 2"): | 35% |
Hardness (Rockwell B Scale): | 90 HRB max |
Fabrication
Alloy 904L is non-magnetic in all conditions and has excellent formability and weldability. The austenitic structure also gives this grade excellent toughness, even down to cryogenic temperatures.
Industry Applications
Chemical Process
Its high chromium and nickel content, along with the addition of molybdenum and copper, help alloy 904L stand up to sulfuric, phosphoric and acetic acids. This is especially useful in the production of acids and fertilizers. See chemical process for more information.
Fabrication
Alloy 904L is used for fabricating parts that will be in contact with sulfuric acid or be used in the production of phosphate-based fertilizers.
Marine
With the addition of copper, alloy 904L’s passive layer gives it better resistance to corrosion in seawater cooling environments compared to 316L and 317L.
Oil & Gas
Resistant to corrosion cracking and crevice corrosion, alloy 904L is used in the oil and gas industry for oil refinery components.
Pulp & Paper
The addition of molybdenum to alloy 904L improved the resistance to localized corrosion, making the alloy ideal for pulp and paper applications such as bleach plant environments and continuous digesters for sulphite pulping.
Power Generation
Alloy 904L has a good resistance to reducing acids as well as chloride attack—properties which are essential in power generation applications like gas scrubbers where inorganic fumes, vapors, and gases are removed.
