Product Description
Alloy 904L (UNS N08904) is a superaustenitic stainless steel contains 14.0-18.0% chromium, 24.0-26.0% nickel, 4.5% molybdenum. It has good activation - passivation conversion ability, excellent corrosion resistance, in non-oxidizing acid such as sulfuric acid, acetic acid, formic acid, phosphoric acid has good corrosion resistance, , in neutral medium containing chloride ion has good pitting resistance, and has good crack corrosion resistance and stress corrosion resistance. Alloy 904L was originally developed to withstand environments containing dilute sulfuric acid. It is used extensively in the chemical process industry including the production of phosphate-based fertilizers.
Alloy 904L is easily welded and processed by standard shop fabrication practices.
Chemical Analysis Weight %
(all values are maximum unless a range is otherwise indicated)
| Nickel | 23.0 min.-28.0 max. | Silicon | 1.00 |
| Chromium | 19.0 min.-23.0 max. | Phosphorus | 0.045 |
| Molybdenum | 4.0 min.-5.0 max. | Sulfur | 0.035 |
| Copper | 1.0-2.0 max. | Iron | Balance |
| Manganese | 2.00 |
Physical Properties
| Temperature Range | |||
| °F | °C | in/in °F | cm/cm °C |
| 68-212 | 20-100 | 8.5 x 10-6 | 15.3 x 10-6 |
Mean Coefficient of Thermal Expansion
| Specific Heat | 0.11 BTU/lb-°F (32 – 212°F) 450 J/kg-°K (0 – 100°C) |
| Modulus of Elasticity | 28.0 x 106 psi 190 GPa |
| Thermal Conductivity 212°F (100°C) | 6.8 BTU/Ft-hr°F 12.9 W/m-°K |
| Melting Range | 2372 – 2534°F 1300 – 1390°C |
| Electrical Resistivity | 33.5 Microhm-in at 68°C 95.2 Microhm-cm at 20°C |
Mechanical Properties
(Typical Values at 68°F (20°C) (minimum values, unless specified)
| Yield Strength 0.2% Offset |
Ultimate Tensile Strength | Elongation in 2 in. |
Hardness | ||
| psi (min.) | (MPa) | psi (min.) | (MPa) | % (min.) | (max.) |
| 31,000 | 220 | 71,000 | 490 | 36 | 70-90 Rockwell B |
Applications
