Hangbo Alloy Group supplies a variety of 630 stainless steel (also known as 17-4PH) products, including round bars, plates, strips, seamless tubes, forgings, and wires. Below is a comprehensive description of 630 stainless steel.
1.Introduction to 630 Stainless Steel
Description: 630 (UNS S17400) is a precipitation-hardening austenitic-ferritic stainless steel, mainly composed of chromium, nickel, copper, and niobium. It is renowned for excellent high strength (achieved via precipitation hardening heat treatment), good corrosion resistance, and stable mechanical properties at medium temperatures (up to 315°C). It balances high tensile strength (over 1000 MPa after aging) and moderate ductility, making it ideal for applications requiring both high structural strength and corrosion resistance.
International Equivalents:
USA: UNS S17400, ASTM 630 (17-4PH)
CHINA: 05Cr17Ni4Cu4Nb (per GB/T 20878 standard)
Europe: EN 1.4542, DIN X5CrNiCuNb16-4
2.Standards for 630/17-4PH
Plates/Sheets: ASTM A693 (Grade S17400), AMS 5604,GB/T4237
Round Bars: ASTM A564 (Grade S17400), AMS 5622,GB/T 1220, EN 10088-3
Seamless Tubes: GB/T 14976, EN 10216-5
Forgings: ASTM A705/A705M (Grade S17400), GB/T 1221, EN 10222-5
3.Chemical Composition of 630/17-4PH
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.07 |
| Chromium (Cr) | 15.0-17.5 |
| Nickel (Ni) | 3.0-5.0 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.04 |
| Sulfur (S) | ≤ 0.03 |
| Iron (Fe) | Balance |
| Niobium(Nb) | 0.15-0.45 |
| Copper(Cu) | 3.0-5.0 |
4.Physical Properties of 630/17-4PH
| Property | Value | |
|---|---|---|
| Density | 7.78 g/cm³ | |
| Melting Range | 1400-1460 °C | |
5.Material Characteristics of 630/17-4PH
High Mechanical Strength: After precipitation hardening (aging treatment), it exhibits ultra-high tensile strength (1000-1300 MPa) and yield strength (800-1100 MPa), far exceeding conventional austenitic stainless steels (e.g., 304, 316).
Corrosion Resistance: Good resistance to atmospheric corrosion, fresh water, and weak corrosive media (e.g., dilute acids, alkalis); performance is between 304 stainless steel and martensitic stainless steel, suitable for non-severe corrosion environments.
Medium-Temperature Stability: Maintains stable strength and toughness at temperatures up to 315°C; no significant creep deformation under long-term medium-temperature service, suitable for medium-temperature structural components.
Controllable Formability: In the solution-annealed state (soft state), it has good cold/hot working performance (e.g., stamping, bending, forging); after aging treatment, hardness increases significantly, limiting secondary processing.
Weldability: Weldable via standard methods (e.g., TIG welding, MIG welding); however, heat input must be controlled to avoid grain coarsening and reduced corrosion resistance; post-weld aging treatment is recommended to restore mechanical properties.
6.Applications of 630/17-4PH
Aerospace & Aviation: Used in aircraft structural components (e.g., brackets, fasteners), engine parts, and missile components; high strength and light weight meet aerospace load requirements.
Petrochemical Industry: Applied to high-pressure valves, pump shafts, pipeline flanges, and wellhead equipment; resists corrosion from oilfield media and maintains strength under high pressure.
Medical Equipment: Employed in surgical instruments (e.g., scissors, forceps), orthopedic implants (e.g., artificial joints), and dental tools; good biocompatibility and corrosion resistance meet medical hygiene standards.
Mechanical Manufacturing: Used in high-strength gears, shafts, bearings, and mold cores; suitable for mechanical parts requiring wear resistance and high load-bearing capacity.
Food & Pharmaceutical Equipment: Applied to high-strength components of food processing machinery (e.g., pressure vessels) and pharmaceutical sterile equipment; corrosion resistance meets food-grade and pharmaceutical-grade requirements.
