904L
904L super austenitic stainless steel is a low-carbon, high-nickel, molybdenum austenitic stainless acid-resistant steel. It is a proprietary material imported from French H·S Company.
It has good activation-passivation transition ability and excellent corrosion resistance. It has excellent properties in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid and phosphoric acid. Very good corrosion resistance, good resistance to pitting corrosion in neutral chlorine containing media, and good resistance to crevice corrosion and stress corrosion. Corrosion performance.
It is suitable for sulfuric acid of various concentrations below 70°C, and can withstand acetic acid of any concentration and temperature under normal pressure, as well as the mixture of formic acid and acetic acid. Corrosion resistance in acids is also very good.
Content
Chemical composition of 904L (%)
| Element | Minimun % | Maximum % |
|---|---|---|
| Cr | 19 | 23 |
| C | - | 0.02 |
| Mn | - | 2 |
| Si | - | 1 |
| P | - | 0.045 |
| S | - | 0.035 |
| Ni | 23 | 28 |
| Mo | 4 | 5 |
| Cu | 1 | 2 |
Physical properties of 904L
| Tensile Strength σb MPa | ≥520 |
|---|---|
| Yield Strength σ0.2MPa | ≥216 |
| Elongation δ5% | ≥35 |
Mechanical properties of 904L alloy
| Density | 8.0 g/cm3 |
|---|---|
| Melting point | 1300-1390 ℃ |
Applications of 904L
1) Petroleum and petrochemical equipment, such as reactors in petrochemical equipment, etc.
2) Sulfuric acid storage and transportation equipment, such as heat exchangers, etc.
3) Power plant flue gas desulfurization device, the main parts used are: the tower body of the absorption tower, flue, baffle plate, internal parts, spray system, etc.
4) Scrubbers and fans in organic acid treatment systems.
5) Seawater treatment equipment, seawater heat exchangers, paper industry equipment, sulfuric acid and nitric acid equipment, acid making, pharmaceutical industry and other chemical equipment Equipment, pressure vessels, food equipment.
6) Pharmaceutical factory: centrifuge, reactor, etc.
7) Plant foods: soy sauce jars, cooking wine, salt shakers, equipment and dressings.
8) 904L is a suitable steel grade for the highly corrosive medium of dilute sulfuric acid.
