What are the differences between 321 stainless steel and 321H stainless steel?
What are the differences between 321 stainless steel and 321H stainless steel?
The main difference between 321 and 321H stainless steel lies in their carbon content: 321 has a maximum carbon content of 0.08%, while 321H has a wider range (0.04-0.10%). This makes 321H perform better in high-temperature applications requiring higher creep resistance and high-temperature strength. Although both are titanium-stabilized austenitic stainless steels designed to prevent intergranular corrosion, 321H still requires a coarser grain size to achieve better high-temperature performance, thus allowing for dual certification in many cases.
Can a magnet attract 316 stainless steel?
Due to its high nickel content, 316 stainless steel is generally considered the "least magnetic" stainless steel. However, 316 stainless steel products that have undergone extensive welding or machining may possess sufficient magnetism to produce a noticeable attraction when brought near a magnet.
Chemical composition of 321 stainless steel and 321H stainless steel
| Element | Stainless Steel 321 | Stainless Steel 321H |
|---|---|---|
| Chromium (Cr) | 17.0 – 19.0 % | 17.0 – 19.0 % |
| Nickel (Ni) | 9.0 – 12.0 % | 9.0 – 12.0 % |
| Carbon (C) | ≤ 0.08 % | 0.04 – 0.10 % |
| Silicon (Si) | ≤ 0.75 % | ≤ 0.75 % |
| Manganese (Mn) | ≤ 2.0 % | ≤ 2.0 % |
| Phosphorus (P) | ≤ 0.045 % | ≤ 0.045 % |
| Sulfur (S) | ≤ 0.03 % | ≤ 0.03 % |
| Titanium (Ti) | ≤ 5 × (C + N) min. – 0.70 | ≤ 4 × (C + N) min. – 0.70 |
Equivalent materials of 316 and 321 stainless steel
| Standard | Stainless Steel 321 | Stainless Steel 321H |
|---|---|---|
| DIN | 1.4541 / 1.4878 | / |
| UNS | S32100 | 321S20 |
| JIS | SUS321 | SUS 321H |
| GB | 06Cr18Ni11Ti | / |
Mechanical Properties of 316 and 321 Stainless Steel
| Property | Value for 321 / 321H |
|---|---|
| Tensile Strength (MPa) | 515 MPa |
| Yield Strength (0.2% Offset, MPa) | 205 MPa |
| Elongation (%) | 40 % |
| Hardness (Brinell) | 217 HB |
Our 321/321H stainless steel is widely used in various industries and fields.
Some application areas are listed below:
Natural gas processing industry,
Petrochemical industry,
Power generation industry,
Food processing industry,
Chemical industry,
Oil and gas industry,
Fertilizer industry
321/321H stainless steel corrosion resistance
321 Stainless Steel
Resistance: Both 321 and 321H stainless steels exhibit excellent corrosion resistance. The titanium stabilization treatment in 321 stainless steel further enhances its protection against oxidation and intergranular corrosion, especially in high-temperature environments and during welding.
321H Stainless Steel
Resistance: Although 321H has similar corrosion resistance to 321, its higher carbon content makes it more susceptible to intergranular corrosion without proper heat treatment. Post-weld annealing may be necessary to restore the corrosion resistance of the heat-affected zone.
Welding Properties of 321/321H Stainless Steel
321 Stainless Steel
Welding Properties: Both 321 and 321H stainless steels can be easily welded using standard welding processes. The lower carbon content of 321 stainless steel minimizes the risk of sensitization during welding, thus reducing the likelihood of intergranular corrosion.
321H Stainless Steel
Welding Properties: Despite its higher carbon content, 321H maintains good weldability. However, care should be taken to avoid overheating during welding. Post-weld annealing is crucial for ensuring optimal corrosion resistance, especially in critical applications.
Typical Applications - 321/321H Stainless Steel
High-Temperature Chemical Processes
Oil Refineries
High-Temperature Steam Applications
Heat Exchanger Tubes
Gnee Steel specializes in the production and sales of a wide range of stainless steel products, including 304, 316, 321, 904, 904L, 2205 duplex stainless steel, and 316L stainless steel. Gnee Steel products are widely used in the kitchen, aerospace, chemical, power, automotive, and nuclear energy industries. We also provide customized stainless steel solutions based on customer needs. For inquiries about stainless steel pricing or customized alloy solutions, please email ru@gneesteelgroup.com for a quote.