Grade 630 Stainless Steel (17-4 PH）

Description

Grade 630, also known as 17-4 PH, is a precipitation-hardening (PH) martensitic stainless steel, renowned for its high strength, good corrosion resistance, and excellent toughness. It gets its name from its composition: 17% chromium, 4% nickel, and copper (3.0-5.0%) as the primary precipitation-hardening element. 630 can be heat-treated (solution annealing followed by aging) to achieve very high strength, while maintaining good corrosion resistance comparable to 304 stainless steel. It is magnetic in the hardened state and has good formability and weldability, though post-weld heat treatment is recommended to restore full strength and corrosion resistance. Unlike other martensitic grades, 630 does not require quenching and tempering for hardening; instead, it is hardened through a low-temperature aging process, which minimizes distortion. It is widely used in applications requiring high strength, good corrosion resistance, and dimensional stability, such as aerospace, automotive, and industrial components.

Chemical Composition (wt%)

C ≤ 0.07, Cr: 15.50-17.50, Ni: 3.00-5.00, Cu: 3.00-5.00, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.040, S ≤ 0.030, Nb+Ta: 0.15-0.45

Mechanical Properties

Tensile Strength ≥ 795 MPa, Yield Strength ≥ 515 MPa, Elongation ≥ 12%, Hardness ≤ 248 HB (annealed); Tensile Strength ≥ 1035 MPa, Yield Strength ≥ 860 MPa, Elongation ≥ 10%, Hardness ≥ 302 HB (aged)

Advantages

High strength after aging; good corrosion resistance (comparable to 304); excellent toughness and dimensional stability; magnetic in hardened state; low-temperature aging (minimizes distortion); good formability and weldability.

Applications

Aerospace components, automotive parts, valves, pumps, shafts, fasteners, surgical instruments, and industrial machinery requiring high strength and good corrosion resistance.

Equivalent Grades

AISI 630 (17-4 PH), UNS S17400, EN 1.4542, GB 05Cr17Ni4Cu4Nb

 

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.