SAE 904L: Chemical Composition, Propertes and Applications

SAE 904L is a non-stabilized austenitic stainless steel alloy that is known for its high corrosion resistance properties. It contains high levels of nickel and molybdenum, which give it excellent resistance to a wide range of corrosive environments. In this article, we will discuss the properties of SAE 904L stainless steel in detail.

Equivalent grades include:

• EN 1.4539 (X1NiCrMoCuN25-20-5)
• UNS N08904
• AISI 904L
• DIN 1.4539
• ASTM A182 F904L
• JIS SUS 890L
• AFNOR Z2 NCDU 25-20

Chemical Composition:

The chemical composition of SAE 904L stainless steel includes high levels of nickel, chromium, and molybdenum. It also contains copper, which enhances its resistance to acids. The low carbon content in the alloy minimizes the risk of intergranular corrosion.

The chemical composition of SAE 904L stainless steel typically includes:

• Carbon (C): Maximum of 0.020%
• Silicon (Si): Maximum of 1.00%
• Manganese (Mn): Maximum of 2.00%
• Phosphorus (P): Maximum of 0.045%
• Sulfur (S): Maximum of 0.035%
• Chromium (Cr): 19.0% - 23.0%
• Nickel (Ni): 23.0% - 28.0%
• Molybdenum (Mo): 4.0% - 5.0%
• Copper (Cu): 1.0% - 2.0%
• Nitrogen (N): Maximum of 0.10%
• Iron (Fe): Balance

Corrosion Resistance: SAE 904L stainless steel is known for its excellent corrosion resistance properties. It is highly resistant to a wide range of corrosive environments, including sulfuric acid, hydrochloric acid, and phosphoric acid solutions. It also has good resistance to pitting and crevice corrosion. The high nickel and molybdenum content in the alloy provide it with excellent resistance to stress corrosion cracking.

Mechanical Properties:

SAE 904L stainless steel has good strength and ductility. Its high tensile strength and yield strength provide the necessary strength for structural applications. The alloy also has good elongation, which means it can undergo plastic deformation without cracking or breaking. The low carbon content in the alloy minimizes the risk of sensitization and intergranular corrosion. The alloy's high nickel and molybdenum content provide it with excellent toughness and resistance to stress corrosion cracking.

The mechanical properties of SAE 904L stainless steel typically include:

• Tensile strength: 490 MPa (71 ksi) minimum
• Yield strength: 220 MPa (32 ksi) minimum
• Elongation: 35% minimum
• Hardness: Brinell 70 maximum; Rockwell B 90 maximum

Physical Properties:

SAE 904L stainless steel has a density of 7.98 g/cm³ (0.289 lb/in³) and a melting point of 1350°C (2460°F). It has a thermal conductivity of 13.1 W/m·K (9.03 BTU/hr·ft·°F) and a specific heat capacity of 500 J/kg·K (0.12 BTU/lb·°F).

Applications:

SAE 904L stainless steel is commonly used in applications that require high corrosion resistance, such as in the chemical processing, oil and gas, and pulp and paper industries. It is also used in medical and laboratory equipment due to its high corrosion resistance and bright finish. The alloy is also used in heat exchangers, condensers, and other equipment that requires high resistance to corrosive environments.

In conclusion, SAE 904L stainless steel is a highly versatile alloy with excellent corrosion resistance properties. Its high nickel and molybdenum content provide it with excellent resistance to a wide range of corrosive environments. The alloy's good mechanical and physical properties make it suitable for use in a wide range of applications, including chemical processing, oil and gas, and medical equipment.

References:

1.     "904L Datasheet" (PDF). Atlas Steels.

2.     ^ "904L Datasheet" (PDF). Rolled Alloys.

3.     ^ "904L Datasheet" (PDF). ATI Metals.