Hangbo Alloy Group supplies a variety of 321 stainless steel products, including round bars, plates, strips, seamless tubes, forgings, and wires. Below is a comprehensive description of 321 stainless steel.
1.Introduction to 321 Stainless Steel
Description: 321 (UNS S32100) is a titanium-stabilized austenitic stainless steel, improved based on 304 stainless steel. It is renowned for excellent intergranular corrosion resistance—titanium in the composition binds with carbon to prevent chromium carbide precipitation (a key cause of intergranular corrosion) in the sensitization temperature range (430-850°C). It maintains stable mechanical properties at medium-high temperatures (up to 870°C), making it ideal for applications requiring corrosion resistance under thermal cycling or long-term medium-high temperature service.
International Equivalents:
USA: UNS S32100, ASTM 321
CHINA: 06Cr18Ni11Ti (per GB/T 20878 standard)
Europe: EN 1.4541, DIN X6CrNiTi18-10
2.Standards for 321 Stainless Steel Products
Plates: ASTM A240/A240M, GB/T 4237, EN 10088-2
Round Bars: ASTM A276, GB/T 1220, EN 10088-3
Seamless Tubes: ASTM A312/A312M, GB/T 14976, EN 10216-5
Forgings: ASTM A182/A182M, GB/T 1221, EN 10222-5
3.Chemical Composition of 321 Stainless Steel
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Chromium (Cr) | 17.0-19.0 |
| Nickel (Ni) | 9.0-12.0 |
| Silicon (Si) | ≤ 0.75 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.03 |
| Iron (Fe) | Balance |
| Nitrogen(N) | ≤ 0.10 |
| Titanium (Ti) | 5*(C+N)-0.7 |
4.Physical Properties of 321 Stainless Steel
| Property | Value |
|---|---|
| Density | 7.98 g/cm³ |
| Melting Range | 1400-1500 °C |
5.Material Characteristics of 321 Stainless Steel
Intergranular Corrosion Resistance: Outstanding resistance to intergranular corrosion—titanium stabilizes carbon, avoiding chromium carbide precipitation at grain boundaries during welding or medium-high temperature service, which is its core advantage over 304 stainless steel.
Oxidation Resistance: Good oxidation resistance at temperatures up to 870°C; forms a dense chromium oxide film on the surface to resist high-temperature gas erosion, with no obvious film spalling under moderate thermal cycling.
Mechanical Strength: Maintains balanced tensile strength, yield strength, and toughness at room and medium-high temperatures (≤870°C); low creep deformation under long-term thermal load, ensuring structural stability of components.
Excellent Formability: Easy to process via cold working (e.g., rolling, stamping, bending) and hot working (e.g., forging, extrusion); can be fabricated into complex-shaped parts without cracking, suitable for customized product manufacturing.
Reliable Weldability: Compatible with standard welding methods (e.g., TIG welding, MIG welding); welded joints retain good intergranular corrosion resistance and mechanical properties (no post-weld heat treatment required for most scenarios), reducing processing costs.
6.Applications of 321 Stainless Steel
Chemical & Petrochemical Industry: Widely used in medium-high temperature corrosive equipment, such as heat exchanger tubes, reaction kettle linings, and pipeline systems for acidic/alkaline media; especially suitable for equipment requiring welding and long-term service at 430-850°C.
Aerospace & Aviation: Applied to high-temperature components of aircraft engines (e.g., exhaust ducts, combustion chamber accessories) and aerospace structural parts; resists thermal cycling corrosion and maintains mechanical stability at medium-high temperatures.
Power Generation Industry: Used in boiler superheater tubes, steam pipelines, and turbine blades of thermal power plants; avoids intergranular corrosion caused by long-term operation at sensitization temperatures.
Food & Pharmaceutical Industry: Employed in high-temperature sterilization equipment (e.g., steam sterilizers, food baking ovens) and pharmaceutical reaction tanks; meets food-grade hygiene standards and resists corrosion from steam and cleaning agents.
Automotive & Marine Industry: Used in automotive exhaust systems (high-temperature sections) and marine engine heat exchangers; resists corrosion from high-temperature exhaust gas and seawater vapor.
