Stainless Steel Grade 17-4PH or Grade 630
Properties and Appearance
Stainless Steel Grade 17-4PH, also known as 17-4 Precipitation Hardening, UNS S17400, or AISI 630, is a martensitic precipitation-hardening stainless steel. It has a metallic silver-grey appearance, similar to other stainless steels with a smooth surface finish which can be polished. It offers a combination of excellent corrosion resistance, high strength, and good mechanical properties. Heat and corrosion profiles are similar to grade 304 steels. Available in solution treated conditions, 17-4PH is easily machined and age-hardened for high strength. Age treatment is handled at low temperatures to avoid distortion.
Grade 17-4PH exhibits good corrosion resistance in mild atmospheric conditions, as well as in freshwater, some acids, and organic substances. Although not as corrosion-resistant as austenitic stainless steels, Grade 17-4PH is known for its high strength, achieved through the precipitation-hardening process. It offers good ductility, allowing for some deformation and forming operations and is magnetic due to its martensitic structure.
The following datasheet provides an overview of stainless steel-grade 17-4PH.
| Element | Content |
| Chromium (Cr) | 15-17% |
| Nickel (Ni) | 3-5% |
| Copper (Cu) | 3-5% |
| Manganese (Mn) | < 1% |
| Silicone (Si) | < 1% |
| Nb + Ta | 0.15-0.45% |
| Carbon (C) | < 0.07% |
| Phosporus (P) | < 0.04% |
| Sulfur (S) | < 0.03% |
| Properties | Metric | Imperial |
| Density | 7750 kg/cm³ |
| Properties | Metric | Imperial |
| Tensile Strength | 930-1310 MPa | |
| Yield Strength (@ strain 0.200%) | 724-1170 MPa | |
| Elastic Modulus | 197 GPa | |
| Hardness, Brinell | 277-363 | |
| Hardness, Rockwell C (converted from Brinell) | 28-40 |
| Properties | Metric | Imperial |
| Thermal Expansion (@100-315°C/212-599°F) | 10.8-11.6µm/m°C | µin/in°F |
| Thermal Conductivity (@100-500°C/212-932°F) | 18-4-22.7 W/mK | BTU in/hr.ft².F |
Fabrication and Heat Treatment
Machinability
17-4PH stainless steels can be machined in the solution-treated condition. Machining rates are similar to 304 steels.
Welding
Grade 17-4PH stainless steels can be welded with all conventional methods without pre-heating. High strength steels should be designed and welded with care to prevent weldment stresses.
Heat Treatment
Condition A: Heat to 1040°C for 0.5 h. Air cool to to 30°C. Small sections can be oil quenched.
Hardening: Age-hardened at low temperatures. Some superficial discoloration can occur, followed by shrinkage at 0.1- 0.05%.
Applications
Stainless Steel Grade 17-4PH finds applications in various industries due to its combination of strength, corrosion resistance, and versatility. Some common uses include:
- Aircraft structure
- Engine parts
- Valves
- Pumps
- Surgical instruments
- Orthopaedic implants
- Food mixers, blenders, and storage tanks
- Molding dies
Formats supplied:
Vulcan Metal Group supplies Stainless Steel Grade 17/4PH bar, sheet, wire, extrusion, pipe, plate and tube. Custom machined and finished parts supplied to print.
Please contact us for a quote or more on how Vulcan Metal Group can help your business.
Address
Vulcan Metal Group LLC
23888 Madison Street
Torrance, CA 90505
United States
Phone / Fax
Phone: +1 310.882.6841
Fax: +1 310.893.0579
Cage Code
8FCY8
Quality Policy: Vulcan Metal Group, LLC. supplies mission critical, special purpose materials, and products at a competitive price. The company’s quality system is registered to ISO 9001 and AS9100 and follows its principles for the governance of the business. An active continual improvement program and compliance with all applicable OSHA, federal, and state regulations is maintained.