Overview of 1.4541 (SS321) Stainless Steel Pipes

1.4541 stainless steel, also known as SS321 or S32100, is an austenitic stainless steel renowned for its excellent resistance to oxidation and high-temperature strength. This alloy is stabilized with titanium, which enhances its resistance to intergranular corrosion. SS321 is widely used in high-temperature environments across various industries due to its favorable mechanical properties and weldability.

Chemical Composition

The chemical composition of SS321 stainless steel is as follows:

• Carbon (C): ≤ 0.08%
• Silicon (Si): ≤ 1.00%
• Manganese (Mn): ≤ 2.00%
• Phosphorus (P): ≤ 0.045%
• Sulfur (S): ≤ 0.030%
• Nickel (Ni): 9.00 – 12.00%
• Chromium (Cr): 17.00 – 19.00%
• Titanium (Ti): ≥ 5 x C

Physical and Mechanical Properties

• Density: 7.9 g/cm³
• Melting Point: 1400-1425°C
• Tensile Strength: ≥ 515 MPa
• Yield Strength: ≥ 205 MPa
• Elongation: ≥ 40%
• Hardness: ≤ 220 HB

Features and Advantages

1. High-Temperature Resistance: SS321 offers excellent oxidation resistance and can withstand temperatures ranging from 800-1500°F (427-816°C).
2. Intergranular Corrosion Resistance: The addition of titanium prevents harmful carbide precipitation during heating and welding, enhancing resistance to intergranular corrosion.
3. Good Mechanical Properties: SS321 maintains good mechanical strength and performance even at elevated temperatures.
4. Weldability: SS321 exhibits good weldability, suitable for most welding techniques.

Applications

Thanks to its excellent properties, SS321 stainless steel pipes are widely used in the following fields:

1. Aerospace: Used for high-temperature structural components and engine parts.
2. Chemical Equipment: Manufacture of reactors, storage tanks, and heat exchangers.
3. Oil and Gas Industry: Used in high-temperature pipelines and equipment in petroleum refining.
4. Food Processing: Manufacture of food processing equipment and storage tanks.
5. Power Plants: Used for high-temperature steam pipes and boiler tubes.

Processing and Manufacturing

SS321 stainless steel pipes can be processed using the following common manufacturing methods:

1. Cold Rolling and Hot Rolling: Pipes of various sizes and specifications can be produced through cold and hot rolling processes.
2. Welding: Due to its good weldability, SS321 is suitable for TIG, MIG, and resistance welding techniques.
3. Machining: SS321 offers good machinability and can be processed using conventional machining methods such as turning, milling, and drilling.

Conclusion

1.4541 (SS321) stainless steel pipe is a high-performance material with excellent high-temperature oxidation resistance and intergranular corrosion resistance. Its superior mechanical properties and weldability make it an important material choice for many high-temperature applications.