AISI 431 is a martensitic chromium-nickel stainless steel with molybdenum that offers high corrosion resistance, acid resistance, wear resistance, and good strength.
Advantages of AISI 431 steel:
- Corrosion resistance: AISI 431 has high corrosion resistance in atmospheric conditions, fresh and salt water, solutions of acids and alkalis, and a number of other aggressive environments.
- Acid resistance: AISI 431 has high resistance to many acids, better than AISI 410.
- Wear resistance: AISI 431 exhibits high wear resistance, making it capable of withstanding significant abrasive loads.
- Strength: AISI 431 possesses good strength at both room and high temperatures.
- Heat resistance: AISI 431 can be used at temperatures up to 870°C without significant oxidation or loss of strength.
- Magnetic properties: AISI 431 is a magnetic steel.
- Machinability: AISI 431 can be machined by various methods, making it suitable for manufacturing complex-shaped parts.
Chemical composition:
| Element | Content, % |
|---|---|
| Chromium | 16-18 |
| Nickel | 1.0-2.0 |
| Molybdenum | 1.0-1.5 |
| Manganese | 1.0 max |
| Silicon | 1.0 max |
| Carbon | 0.12-0.25 |
| Nitrogen | 0.04-0.10 |
| Copper | 0.50 max |
| Sulfur | 0.030 max |
| Phosphorus | 0.030 max |
| Iron | remainder |
Mechanical properties:
| Property | Value |
|---|---|
| Tensile strength | 750-950 MPa |
| Brinell hardness | 220-280 HB |
| Elongation at break | 12-20% |
| Impact toughness | 80-120 J/cm² |
Physical properties:
| Property | Value |
|---|---|
| Density | 7.7 g/cm³ |
| Melting point | 1450°C |
| Thermal conductivity | 26.9 W/(m·K) |
| Electrical resistivity | 1.05 μΩm |
Analogues:
| Country | Analogue |
|---|---|
| USA | AISI 431 |
| European Union | EN 1.4057 |
| Ukraine | 20Х17Н2 |
Most common applications of AISI 431:
- Corrosion-resistant products:
- Knife blades
- Surgical instruments
- Machine parts
- Piping elements
- Wear-resistant products:
- Shafts
- Gears
- Bearings
- Dies
- Heat-resistant products:
- Furnace parts
- Heat-resistant parts
- Exhaust system elements
- Decorative elements:
- Architectural elements
- Cladding
- Decorative details (with additional surface treatment)
AISI 431 STEEL is a versatile material with improved corrosion and acid resistance compared to AISI 410. It is suitable for applications requiring high corrosion resistance, wear resistance, strength, and heat resistance at moderate temperatures.
Important notes:
- AISI 431 steel has low oxidation resistance at temperatures above 870°C.
- Due to its magnetic properties, AISI 431 is not recommended for use in some electrical applications.
- To obtain maximum corrosion resistance, AISI 431 can be heat treated - hardened and tempered.
When choosing stainless steel, it is important to consider the operating conditions and required properties. AISI 431 can be an optimal choice for applications where improved corrosion and acid resistance compared to AISI 410 is required, as well as high wear resistance, strength, and heat resistance at moderate temperatures. For applications requiring oxidation resistance at high temperatures or non-magnetic properties, other stainless steel grades should be considered.