Grade SUS440B Stainless Steel

Description

Grade SUS440B is a medium-carbon martensitic stainless steel, positioned between SUS440A and SUS440C in terms of carbon content (0.75-0.95%) and performance. It retains the 16.0-18.0% chromium content of the SUS440 series, providing good corrosion resistance in mild to moderate environments, and includes a small amount of molybdenum (0.75-1.25%) to enhance wear resistance and pitting resistance compared to SUS440A. As a martensitic grade, it is magnetic and can be heat-treated to achieve higher hardness and wear resistance than SUS440A, while remaining more formable than SUS440C. SUS440B is ideal for applications where a step up in wear resistance from SUS440A is needed, without sacrificing too much processability. It is commonly used in industrial components that operate in dry or slightly corrosive conditions, where durability and wear resistance are key priorities.

Chemical Composition (wt%)

C: 0.75-0.95, Cr: 16.00-18.00, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.045, S ≤ 0.030, Mo: 0.75-1.25, Ni ≤ 0.75

Mechanical Properties

Tensile Strength ≥ 860 MPa, Yield Strength ≥ 620 MPa, Elongation ≥ 8%, Hardness ≤ 285 HB (annealed); Tensile Strength ≥ 1250 MPa, Yield Strength ≥ 960 MPa, Elongation ≥ 6%, Hardness 56-60 HRC (heat-treated)

Advantages

Higher wear resistance than SUS440A; better pitting resistance due to molybdenum addition; heat-treatable to high hardness; magnetic; balanced processability (formability/weldability) between SUS440A and SUS440C; good corrosion resistance in mild to moderate environments.

Applications

High-performance blades, knives, bearings, valves, gears, pump parts, and industrial components requiring enhanced wear resistance compared to SUS440A.

Equivalent Grades

AISI 440B, UNS S44003, EN 1.4125, GB 8Cr17

 

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.