Grade SUS431 Stainless Steel

Description

Grade SUS431 is a nickel-bearing martensitic stainless steel, offering improved toughness, ductility, and corrosion resistance compared to standard martensitic grades like SUS410 and SUS420. It contains 15.0-17.0% chromium and 1.25-2.50% nickel, which enhances its toughness and corrosion resistance, making it suitable for high-stress structural components. As a martensitic grade, SUS431 is magnetic and can be heat-treated to achieve high strength and hardness while maintaining good toughness- a key advantage over other martensitic grades. It has better weldability than SUS410 and SUS420, though post-weld heat treatment is still recommended to restore corrosion resistance. Unlike austenitic grades, SUS431 is cost-effective and prioritizes strength and toughness, making it widely used in automotive, aerospace, and industrial applications where high stress and moderate corrosion resistance are required.

Chemical Composition (wt%)

C ≤ 0.20, Cr: 15.00-17.00, Ni: 1.25-2.50, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.040, 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 SUS410/SUS420; 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.