Grade 431 Stainless Steel

Description

Grade 431 is a martensitic stainless steel with added nickel (1.25-2.50%), which enhances its toughness, corrosion resistance, and ductility compared to other martensitic grades like 410 and 420. It contains 15.0-17.0% chromium, providing good corrosion resistance in mild to moderate corrosive environments, and is magnetic due to its martensitic structure. 431 can be heat-treated to achieve high strength and hardness while maintaining good toughness, making it suitable for applications requiring a balance of strength, corrosion resistance, and ductility. It has better weldability than 410 and 420, though post-weld heat treatment is still recommended to restore corrosion resistance. 431 is widely used in industrial applications where higher strength and corrosion resistance than standard martensitic grades are required, such as automotive components, aerospace parts, and industrial machinery.

Chemical Composition (wt%)

C ≤ 0.20, Cr: 15.00-17.00, Ni: 1.25-2.50, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.045, S ≤ 0.030

Mechanical Properties

Tensile Strength ≥ 725 MPa, Yield Strength ≥ 515 MPa, Elongation ≥ 15%, Hardness ≤ 241 HB (annealed); Tensile Strength ≥ 1000 MPa, Yield Strength ≥ 700 MPa, Elongation ≥ 10%, Hardness ≥ 285 HB (heat-treated)

Advantages

Higher toughness and ductility than 410/420; better corrosion resistance than standard martensitic grades; heat-treatable for high strength; magnetic; good weldability (with post-weld heat treatment); suitable for high-stress applications.

Applications

Automotive parts (axles, gears), aerospace components, valves, pumps, shafts, fasteners, and industrial machinery parts requiring high strength and moderate corrosion resistance.

Equivalent Grades

AISI 431, UNS S43100, EN 1.4057, GB 17Cr16Ni2

 

Stainless Steel Suppliers

If you have project requirements for stainless steel, 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 information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.