1.4057 / UNS S43100 / AISI 431 equivalent material
What is 431 stainless steel?
431 stainless steel is a martensitic stainless steel that possesses high strength and toughness, making it ideal for demanding applications such as aerospace fasteners, marine fittings, and pump/valve shafts. It can achieve high hardness through heat treatment (up to approximately 40 HRC) and exhibits good corrosion resistance to seawater and many organic/petroleum products. However, due to its high yield strength, it is not suitable for welding or cold forming.
What type of stainless steel is SS 431?
431 stainless steel is a martensitic stainless steel that is AOD melted. This alloy has excellent corrosion resistance for a 400 series stainless and can be heat treated to high strength levels. This grade is often used in the aerospace industry as fittings and boltings requiring high yield strength.
What is the material equivalent of AISI 431?
AISI 431, which is equivalent to 1.4057, BS 431S29, and X17CrNi16-2, is a stainless martensitic chromium-nickel steel with a chromium content of 15-17%. Due to the high chromium content, this stainless steel has better corrosion resistance and toughness than comparable steels with a lower chromium content. It can be processed into various practical product forms, including plates, coils, tubes, bars, and wires.
Chemical composition and properties of stainless steel AISI 431 (1.4057 / BS 431S29)
|
C |
Si |
Mn |
P |
S |
N |
Cr |
Cu |
Mo |
Ni |
Ti |
|---|---|---|---|---|---|---|---|---|---|---|
|
0,12 - 0,22 |
≤ 1,00 |
≤ 1,50 |
≤ 0,04 |
≤ 0,03 |
- |
15,0 - 17,0 |
- |
- |
1,50 - 2,50 |
- |
Minimum values of the 0.2 % proof stress at elevated temperatures
|
Temp in °C |
100 °C |
150 °C |
200 °C |
250 °C |
300 °C |
350 °C |
400 °C |
|---|---|---|---|---|---|---|---|
|
+QT900 |
565 |
525 |
505 |
490 |
470 |
430 |
375 |
|
+QT800 |
515 |
495 |
475 |
460 |
440 |
405 |
355 |
stainless steel AISI 431 Corrosion resistance
AISI 431 stainless steel offers good corrosion resistance in mildly corrosive environments, with its high chromium content (~15–17%) providing better resistance than 410 and 420 grades, but it is less resistant than austenitic grades like 304 or 316, especially in chloride-rich or marine conditions.
Welding Properties of AISI 431 / 1.4057 Stainless Steel
AISI 431 (1.4057, BS 431S29, X17CrNi16-2) material is suitable for certain welding processes, but some precautions must be observed. When welding this material, gases containing hydrogen or nitrogen should not be used. If filler metal is required, 1.4430 (AISI AWS316L) or 1.4370 material should be used, especially when high weld strength is not required.
Heat treatment and hot forming
Hot forming: 800-1100 °C | Type of cooling: slow cooling
Annealing: 680-800 °C | Cooling type: furnace, air
Applications for stainless steel AISI 431 / 1.4057
Stainless Steel AISI 431 / EN 1.4057 is widely used for high-strength components such as pump and valve shafts, aircraft fittings, fasteners, marine hardware, and drive shafts, where its tensile strength can exceed 900–1,000 MPa after heat treatment while still providing moderate corrosion resistance in atmospheric and mildly corrosive environments.
What is the difference between 316 and 431 stainless steel?
The key difference between 316 and 431 stainless steel is that 316 offers superior corrosion resistance due to its 2–3% molybdenum content, while 431 provides much higher strength, achieving >900 MPa tensile strength after heat treatment, but with lower chloride and marine corrosion resistance compared to 316.
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why choose our products
If you have project requirements for 431 1.4057 stainless steel bars, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition and free samples, please contact our factory immediately. We offer competitive prices and excellent service.
