Product Description
17-4PH (also known as 630, 1.4542, or X5CrNiCuNb16-4) is a premium precipitation hardening martensitic stainless steel that combines high strength, excellent toughness, and good corrosion resistance. This versatile alloy contains approximately 17% chromium, 4% nickel, 4% copper, and small additions of niobium (columbium) to achieve its remarkable mechanical properties through a simple heat treatment process. The “PH” in its designation stands for “precipitation hardening,” which refers to the strengthening mechanism that gives this material its exceptional combination of properties.
In its solution annealed condition, 17-4PH is relatively soft and machinable. After a simple, low-temperature aging treatment, the alloy develops high strength and hardness while maintaining good corrosion resistance. This unique characteristic allows fabricators to form, machine, or weld the material in its annealed state and then perform a single, low-temperature heat treatment to develop the desired mechanical properties with minimal distortion.
The corrosion resistance of 17-4PH is comparable to that of austenitic Type 304 stainless steel in most environments and is generally superior to that of the hardenable 400 series stainless steels. This combination of high strength and good corrosion resistance makes 17-4PH an ideal choice for applications in aerospace, medical, defense, chemical processing, petroleum, food processing, and general industrial sectors where both properties are essential.
FUSHUN METAL supplies 17-4PH stainless steel in various product forms to meet the diverse requirements of demanding applications. Our high-quality material provides reliable performance in critical components where the combination of strength, toughness, and corrosion resistance is paramount.
Applications
17-4PH stainless steel is widely used across multiple industries due to its exceptional combination of high strength, good corrosion resistance, and favorable fabrication characteristics. The material is particularly valuable in applications requiring high mechanical properties and moderate corrosion resistance at service temperatures up to 600°F (315°C).
Key applications for 17-4PH stainless steel include:
- Aerospace Industry: Aircraft structural components, landing gear parts, fasteners, turbine blades, jet engine components, and helicopter deck platforms where high strength-to-weight ratio and good corrosion resistance are essential.
- Medical and Biomedical Sector: Surgical instruments, dental tools, orthopedic devices, and medical equipment components that require high strength, corrosion resistance, and the ability to be sterilized repeatedly.
- Oil and Gas Production: Valves, pump shafts, fittings, fasteners, and downhole components exposed to corrosive environments where both strength and corrosion resistance are critical.
- Chemical Processing: High-pressure valves, fittings, pump components, and fasteners used in chemical processing equipment handling moderately corrosive media.
- Food Processing: Machinery parts, pump components, valves, and fasteners in food processing equipment where strength and corrosion resistance are required.
- Marine Applications: Propeller shafts, valve stems, fasteners, and structural components in marine environments where good resistance to seawater corrosion is needed.
- Nuclear Industry: Various components in nuclear waste processing and storage systems that require high reliability and good corrosion resistance.
- Defense Industry: Various structural and mechanical components in military equipment and weapons systems.
- Mechanical Engineering: Gears, shafts, plungers, bushings, fasteners, and other high-strength components requiring good wear resistance and dimensional stability.
- Tooling Applications: Molds, dies, and tooling components benefiting from the material’s high hardness, good wear resistance, and dimensional stability during heat treatment.
The versatility of 17-4PH stainless steel makes it an excellent choice for applications where conventional austenitic stainless steels lack sufficient strength and where conventional martensitic stainless steels lack adequate corrosion resistance or toughness. Its ability to be machined in the annealed condition and then hardened with minimal distortion provides significant manufacturing advantages in producing complex, precision components.
Standards
17-4PH stainless steel conforms to numerous international standards and specifications, ensuring consistent quality and performance in demanding applications:
American Standards:
- ASTM A564/A564M – Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes (Type 630)
- ASTM A693/A693M – Standard Specification for Precipitation-Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip (Type 630)
- ASTM A705/A705M – Standard Specification for Age-Hardening Stainless Steel Forgings (Type 630)
- AMS 5604 – Steel, Corrosion and Heat Resistant, Sheet, Strip, and Plate, 16Cr – 4.0Ni – 4.0Cu – 0.30Cb
- AMS 5643 – Steel, Corrosion and Heat Resistant, Bars, Wire, Forgings, Tubing, and Rings, 16Cr – 4.0Ni – 4.0Cu – 0.30Cb
- AMS 5825 – Steel, Corrosion and Heat Resistant, Welding Wire, 16Cr – 4.0Ni – 4.0Cu – 0.30Cb
- ASME SA-564/SA-564M – Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes (Type 630)
- ASME SA-693/SA-693M – Specification for Precipitation-Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip (Type 630)
- ASME SA-705/SA-705M – Specification for Age-Hardening Stainless Steel Forgings (Type 630)
European Standards:
- EN 10088-3 – Stainless steels – Part 3: Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion resisting steels for general purposes (1.4542)
- EN 10151 – Stainless steel strip for springs (1.4542)
- EN 10263-5 – Steel rod, bars and wire for cold heading and cold extrusion (1.4542)
International Standards:
- ISO 683-13 – Heat-treatable steels, alloy steels and free-cutting steels (X5CrNiCuNb16-4)
- UNS S17400 – Unified Numbering System for Metals and Alloys
Japanese Standards:
- JIS G4304 – Hot-rolled stainless steel plate, sheet and strip (SUS630)
- JIS G4305 – Cold-rolled stainless steel plate, sheet and strip (SUS630)
- JIS G4308 – Stainless steel wire rods (SUS630)
- JIS G4303 – Stainless steel bars (SUS630)
Industry-Specific Standards:
- NACE MR0175/ISO 15156 – Materials for use in H₂S-containing environments in oil and gas production
- ASTM F899 – Standard Specification for Wrought Stainless Steels for Surgical Instruments
These comprehensive standards ensure that 17-4PH stainless steel from FUSHUN METAL meets the rigorous requirements for use in critical applications across various industries.
Material Designation and Chemical Composition
17-4PH stainless steel is known by various designations in different standards and specification systems:
| Standard System | Designation |
|---|---|
| UNS | S17400 |
| AISI/SAE | 630 |
| EN/DIN | 1.4542 |
| ISO | X5CrNiCuNb16-4 |
| JIS | SUS630 |
| AFNOR | Z7 CNU 16-04 |
The chemical composition of 17-4PH stainless steel is carefully controlled to ensure optimal performance in demanding applications:
| Element | Minimum (%) | Maximum (%) |
|---|---|---|
| Carbon (C) | – | 0.07 |
| Chromium (Cr) | 15.0 | 17.5 |
| Nickel (Ni) | 3.0 | 5.0 |
| Copper (Cu) | 3.0 | 5.0 |
| Niobium (Columbium) + Tantalum (Nb+Ta) | 0.15 | 0.45 |
| Manganese (Mn) | – | 1.0 |
| Silicon (Si) | – | 1.0 |
| Phosphorus (P) | – | 0.04 |
| Sulfur (S) | – | 0.03 |
| Iron (Fe) | Balance | – |
The carefully balanced composition of 17-4PH stainless steel, with its high chromium content for corrosion resistance and strategically added copper and niobium for precipitation hardening capability, provides the unique combination of properties that make this alloy valuable for demanding applications requiring both high strength and good corrosion resistance.
Physical and Mechanical Properties
17-4PH stainless steel offers an exceptional combination of high strength, good corrosion resistance, and excellent fabricability. The mechanical properties can be tailored through various aging heat treatments to meet specific application requirements.
Physical Properties
| Property | Value |
|---|---|
| Density | 7.8 g/cm³ (0.282 lb/in³) |
| Melting Range | 1404-1440°C (2560-2625°F) |
| Modulus of Elasticity | 196 GPa (28.5 × 10⁶ psi) |
| Electrical Resistivity at 20°C | 0.80 Ω·mm²/m (31.5 μΩ·in) |
| Thermal Conductivity at 100°C | 18.3 W/m·K (10.6 BTU·in/ft²·hr·°F) |
| Coefficient of Thermal Expansion (20-100°C) | 10.8 × 10⁻⁶ /K (6.0 × 10⁻⁶ /°F) |
| Specific Heat Capacity at 20°C | 460 J/kg·K (0.11 BTU/lb·°F) |
| Magnetic Permeability | Ferromagnetic in all conditions |
Mechanical Properties
The mechanical properties of 17-4PH stainless steel vary significantly based on the heat treatment condition. Below are typical properties for various common heat treatment conditions:
| Condition | Ultimate Tensile Strength, MPa (ksi) | 0.2% Yield Strength, MPa (ksi) | Elongation in 50mm (2″), % | Hardness, HBW (HRC) |
|---|---|---|---|---|
| Solution Annealed (Condition A) | 1030 (150) | 760 (110) | 8 | 330 (33) |
| H900 (aged at 482°C/900°F) | 1310-1380 (190-200) | 1170-1280 (170-185) | 10-14 | 388-444 (40-44) |
| H925 (aged at 496°C/925°F) | 1310 (190) | 1210 (175) | 14 | 388-444 (40-44) |
| H1025 (aged at 552°C/1025°F) | 1170 (170) | 1140 (165) | 15 | 331-388 (36-40) |
| H1075 (aged at 580°C/1075°F) | 1140 (165) | 1030 (150) | 16 | 321-375 (35-38) |
| H1150 (aged at 621°C/1150°F) | 1000 (145) | 860 (125) | 19 | 311 (33) |
| H1150D (double aged at 621°C/1150°F) | 965 (140) | 827 (120) | 22 | 294 (31) |
Heat Treatment
17-4PH stainless steel achieves its high strength through a simple heat treatment process that involves solution annealing followed by aging (precipitation hardening). The standard heat treatment procedures include:
- Solution Annealing (Condition A): Heating to 1038°C (1900°F) for 30 minutes followed by air cooling or oil quenching to below 32°C (90°F). This creates a martensitic structure.
- Aging Treatment: Solution-annealed material is subjected to one of several aging treatments to develop the desired combination of strength, hardness, and toughness. Common aging treatments include:
- H900: Aging at 482°C (900°F) for 1 hour, followed by air cooling. Produces maximum hardness but lower toughness.
- H925: Aging at 496°C (925°F) for 4 hours, followed by air cooling.
- H1025: Aging at 552°C (1025°F) for 4 hours, followed by air cooling.
- H1075: Aging at 580°C (1075°F) for 4 hours, followed by air cooling.
- H1150: Aging at 621°C (1150°F) for 4 hours, followed by air cooling.
- H1150D: Double aging at 621°C (1150°F) for 4 hours, air cooling, followed by a second 4-hour treatment at 621°C (1150°F) and air cooling.
- H1150M: Aging at 760°C (1400°F) for 2 hours, air cooling, followed by 621°C (1150°F) for 4 hours and air cooling.
The aging treatment temperature determines the final mechanical properties. Lower aging temperatures (H900, H925) produce higher strength and hardness but lower toughness and ductility. Higher aging temperatures (H1075, H1150) result in improved toughness and ductility at the expense of some strength. H1150 and H1150D conditions provide the best combination of toughness and resistance to stress corrosion cracking, making them preferred for applications in aggressive environments.
It’s important to note that 17-4PH should not generally be used in the solution-annealed condition (Condition A). In this condition, the material has an untempered martensite structure with low toughness and is more susceptible to stress corrosion cracking than aged material.
Available Dimensions
FUSHUN METAL supplies 17-4PH stainless steel in a wide range of product forms and dimensions to meet diverse application requirements:
Plate and Sheet
| Product Form | Thickness | Width | Length |
|---|---|---|---|
| Plate | 4.0 mm – 100 mm (0.157″ – 4″) | Up to 2,500 mm (98″) | Up to 10,000 mm (394″) |
| Sheet | 0.5 mm – 4.0 mm (0.020″ – 0.157″) | Up to 1,500 mm (59″) | Up to 6,000 mm (236″) |
| Strip | 0.1 mm – 3.0 mm (0.004″ – 0.118″) | Up to 500 mm (20″) | Coil form or cut lengths |
Bar and Rod
| Product Form | Diameter/Dimension | Length |
|---|---|---|
| Round Bar | 5 mm – 300 mm (0.197″ – 12″) | Up to 6,000 mm (236″) |
| Square Bar | 10 mm – 150 mm (0.394″ – 6″) | Up to 6,000 mm (236″) |
| Flat Bar | Thickness: 5 mm – 50 mm (0.197″ – 2″) Width: 10 mm – 200 mm (0.394″ – 8″) |
Up to 6,000 mm (236″) |
| Hexagonal Bar | 10 mm – 100 mm (0.394″ – 4″) across flats | Up to 6,000 mm (236″) |
| Wire | 0.5 mm – 12 mm (0.020″ – 0.472″) | Coil form or cut lengths |
Tube and Pipe
| Product Form | Outside Diameter | Wall Thickness | Length |
|---|---|---|---|
| Seamless Tube | 6 mm – 150 mm (0.236″ – 6″) | 0.5 mm – 10 mm (0.020″ – 0.394″) | Up to 12,000 mm (472″) |
| Welded Tube | 10 mm – 300 mm (0.394″ – 12″) | 0.5 mm – 10 mm (0.020″ – 0.394″) | Up to 12,000 mm (472″) |
Forgings and Special Shapes
FUSHUN METAL also provides custom forgings and special shapes in 17-4PH stainless steel according to customer specifications:
- Open die forgings
- Closed die forgings
- Rings and discs
- Custom profiles
- Machined components
All products are supplied in the solution annealed condition (Condition A) unless otherwise specified. Age hardening heat treatments can be performed upon request to achieve specific mechanical properties. Custom dimensions, tolerances, and surface finishes are available to meet your specific requirements.
Fabrication Information
17-4PH stainless steel can be fabricated using conventional methods, but there are some important considerations to ensure optimal performance of the finished components:
Machining
17-4PH stainless steel has good machinability in the solution-annealed condition (Condition A), similar to that of Type 304 stainless steel. The following recommendations apply:
- Both high-speed steel and carbide tools are suitable for machining 17-4PH.
- Rigid tooling setups are recommended to minimize vibration.
- Use standard cutting fluids and lubricants for stainless steels.
- Machining after age hardening is possible but more difficult, requiring slower speeds and more rigid setups.
- When tight tolerances are required, allow for the slight dimensional change (0.05-0.10% shrinkage) that occurs during age hardening.
Forming
17-4PH has limited cold formability compared to austenitic stainless steels:
- Cold Forming: Should be performed only in the solution-annealed condition. Complex or severe forming operations may not be possible due to the material’s high strength and limited ductility.
- Hot Forming: Can be performed at temperatures between 950-1200°C (1742-2192°F). Material should be uniformly heated and must be solution annealed after hot forming, followed by appropriate age hardening.
- After cold forming, stress corrosion resistance is improved by re-aging at the precipitation hardening temperature.
Welding
17-4PH can be readily welded using most standard welding processes:
- Suitable welding processes include GTAW (TIG), GMAW (MIG), SMAW (stick), PAW (plasma arc), and others.
- The recommended filler metal is typically 17-4PH or 17-7PH to match the base metal properties.
- Preheating is generally not required unless the material temperature is below 16°C (60°F).
- Post-weld heat treatment (solution annealing followed by age hardening) is recommended for optimal properties in the weld area.
- Welding in the aged condition is possible but may reduce toughness in the heat-affected zone.
Heat Treatment
Proper heat treatment is critical to achieving the desired properties in 17-4PH components:
- Solution annealing should be performed at 1038°C (1900°F) for 30 minutes per 25mm (1 inch) of thickness, followed by rapid cooling to below 32°C (90°F).
- Age hardening temperatures and times should be carefully controlled to achieve the desired combination of strength and toughness.
- A slight dimensional change (shrinkage) of approximately 0.05-0.10% occurs during age hardening and should be considered in design.
- Components should not be placed into service in the solution-annealed condition due to the untempered martensitic structure, which has lower toughness and greater susceptibility to stress corrosion cracking.
Surface Finishing
17-4PH stainless steel can be finished using standard methods for stainless steels:
- Mechanical polishing
- Electropolishing
- Passivation is recommended after fabrication to ensure optimal corrosion resistance
- Chemical pickling and cleaning
- Abrasive blasting
Corrosion Resistance and Service Limitations
17-4PH stainless steel offers good corrosion resistance properties that make it suitable for a wide range of applications, but it also has important service limitations that should be considered:
Corrosion Resistance
- The corrosion resistance of 17-4PH is comparable to that of Type 304 stainless steel in most environments and generally superior to that of the hardenable 400 series stainless steels.
- The alloy provides good resistance to atmospheric corrosion, fresh water, and many mild chemical environments.
- In the age-hardened condition, 17-4PH exhibits good resistance to general corrosion in various industrial environments, including mild acids, alkalis, and salts.
- The material’s corrosion resistance is typically better in the age-hardened condition than in the solution-annealed condition.
- Higher aging temperatures (H1150, H1150D) generally provide better resistance to stress corrosion cracking than lower aging temperatures (H900, H925).
Service Limitations
- Temperature Limitations: 17-4PH should not be used at temperatures above 315°C (600°F) for extended periods as this can adversely affect the precipitation-hardened structure and reduce mechanical properties.
- Cryogenic Use: The material is generally not recommended for cryogenic service due to its reduced toughness at very low temperatures.
- Chloride Environments: In warm chloride environments, 17-4PH is susceptible to pitting and crevice corrosion. For improved resistance to chloride stress corrosion cracking, the higher aging temperatures (above 550°C/1022°F) are recommended.
- Seawater Service: While 17-4PH offers moderate resistance to seawater, it is susceptible to crevice corrosion and pitting when exposed to stagnant seawater for extended periods.
- Solution-Annealed Condition: The material should not be used in the solution-annealed condition (Condition A) due to its untempered martensitic structure, which has lower toughness and increased susceptibility to stress corrosion cracking.
Application Recommendations
- For applications with exposure to chlorides or potential stress corrosion cracking, the H1150 or H1150D conditions are preferred over the higher-strength conditions.
- In sulfide-containing environments (H₂S), the H1150 condition aged at 590°C (1094°F) is recommended.
- For maximum corrosion resistance, components should be properly passivated after all fabrication operations.
- When welding is required, post-weld heat treatment (solution annealing followed by age hardening) is recommended to ensure optimal corrosion resistance in the welded area.
- Design considerations should include avoiding crevices, stagnant areas, and other features that may promote localized corrosion.
Why Choose FUSHUN METAL for 17-4PH Stainless Steel
When selecting a supplier for premium 17-4PH precipitation hardening stainless steel, FUSHUN METAL stands as your preferred partner for several compelling reasons:
Superior Quality Assurance
At FUSHUN METAL, we implement rigorous quality control processes throughout our production chain. Our 17-4PH stainless steel undergoes comprehensive testing including chemical analysis, mechanical testing, microstructure examination, and corrosion testing to ensure full compliance with international standards and specifications. This meticulous attention to quality guarantees that our products consistently deliver the exceptional performance required in the most demanding applications.
Metallurgical Expertise
Our team of metallurgical specialists possesses extensive experience and knowledge in the production and processing of precipitation hardening stainless steels. This expertise enables us to provide valuable technical support to help you select the optimal material specifications and heat treatment conditions for your specific application requirements. We understand the critical factors that influence the performance of 17-4PH stainless steel and can help you optimize your designs to take full advantage of its superior properties.
Comprehensive Product Range
FUSHUN METAL offers one of the most extensive ranges of 17-4PH stainless steel products available, including plate, sheet, strip, bar, tube, wire, and custom components. This diverse product portfolio allows you to source all your precipitation hardening stainless steel requirements from a single, reliable supplier, streamlining your procurement process and ensuring consistency across your projects.
Heat Treatment Capabilities
We provide 17-4PH stainless steel in both the solution-annealed condition and in various age-hardened conditions to meet your specific strength and corrosion resistance requirements. Our advanced heat treatment facilities ensure precise control of temperatures and processing parameters, resulting in consistent and predictable material properties. Whether you need maximum strength (H900) or optimized stress corrosion resistance (H1150), we can deliver the exact properties your application demands.
Value-Added Services
Beyond supplying premium materials, we offer a range of value-added services including custom cutting, machining, heat treatment, surface finishing, and non-standard dimensions to meet your specific requirements. Our ability to provide tailored solutions helps you optimize your manufacturing processes and reduce overall costs.
For your next project requiring the exceptional combination of high strength and good corrosion resistance that 17-4PH stainless steel provides, we invite you to contact our technical team to discuss your specific requirements. Our experts are ready to help you select the optimal material specifications and heat treatment conditions, providing the premium quality products you need for reliable, long-term performance in even the most demanding applications.
