17-4PH Stainless Steel Plate – High-Strength Precipitation Hardening Alloy
Sandmeyer Steel Company stocks a large inventory of 17-4PH stainless steel plate in the annealed condition in thicknesses from 3/16″ through 4″, ready to be processed and shipped to your specific requirements.
Available thicknesses for Alloy 17-4PH:
| 3/16" | 1/4" | 5/16" | 3/8" | 7/16" | 1/2" | 9/16" | 5/8" | 3/4" | 7/8" | 1" |
| 4.8mm | 6.3mm | 7.9mm | 9.5mm | 11.1mm | 12.7mm | 14.3mm | 15.9mm | 19mm | 22.2mm | 25.4mm |
| 1 1/8" | 1 1/4" | 1 1/2" | 1 3/4" | 2" | 2 1/4" | 2 1/2" | 2 3/4" | 3" | 3 1/2" | 4" |
| 28.6mm | 31.8mm | 38.1mm | 44.5mm | 50.8mm | 57.2mm | 63.5mm | 69.9mm | 76.2mm | 88.9mm | 101.6mm |
Alloy 17-4PH is a precipitation hardening martensitic stainless steel with Cu and Nb/Cb additions. The grade combines high strength, hardness (up to 572°F /300°C), and corrosion resistance. Mechanical properties can be optimized with heat treatment. Very high yield strength up to 1100-1300 MPa (160-190 ksi) can be achieved.
Specification Sheet Overview
for Alloy 17-4PH (UNS S17400)
W. Nr. 1.4542 Type 630:
A Precipitation-Hardening Martensitic Stainless with High Strength and Hardness and Good Corrosion Resistance
General Properties
Alloy 17-4PH (UNS S17400), Type 630, is a chromium-nickel-copper precipitation-hardening martensitic stainless steel with an addition of niobium. 17-4PH combines high strength and hardness with good corrosion resistance.
The alloy is furnished in the solution annealed condition (Condition A). It should not be used at temperatures above 572°F (300°C) or for cryogenic service. Optimal mechanical properties can be obtained by subjecting the alloy to age hardening heat treatments. Heat treatment in the 900°F (482°C) range produces the highest strength.
The corrosion resistance of Alloy 17-4PH is comparable to 304 stainless steel in most environments, and is generally superior to the 400 series stainless steels. It is used in applications where the combination of moderate corrosion resistance and unusually high strength are required.
Alloy 17-4PH can be easily welded and processed by standard shop fabrication practices. It is magnetic.
Corrosion Resistance
The corrosion resistance of Alloy 17-4PH is comparable to 304 stainless steel in most environments, and is generally superior to the 400 series stainless steels. It is used in applications where the combination of moderate corrosion resistance and unusually high strength are required. Alloy 17-4PH has corrosion resistance comparable to 304L in some chemical, dairy, food, paper and petroleum applications.
Alloy 17-4PH in the solution-annealed condition (Condition A) should not generally be put in service. The alloy is subject to brittle fractures and more sensitive to chloride stress corrosion cracking than the aged material.
If risks of chloride stress corrosion cracking are present the higher aging temperatures should be selected over 1022°F (550°C), preferably 1094°F (590°C). 1022°F (550°C) is the recommended tempering temperature in chloride service. 1094°F (590°C) is preferred in H2S media.
Alloy 17-4PH is subject to crevice corrosion and pitting attack when exposed to stagnant seawater for a duration of time.
Chemical Analysis
Weight % (all values are maximum unless a range is otherwise indicated)
| Chromium | 15.0 min.-17.5 max. | Phosphorus | 0.04 |
| Nickel | 3.0 min.-5.0 max. | Sulfur | 0.03 |
| Copper | 3.0 min.-5.0 max. | Silicon | 1.0 |
| Carbon | 0.07 | Nobium plus Tantalum | 0.15 min.-0.45 max. |
| Manganese | 1.0 | Iron | Balance |
Density
0.280 lbs/in3
7.75 g/cm3
Specific Heat
0.11 BTU/lb-°F @ 70°F)
460 J/kg-°C @ 20°C)
Modulus of Elasticity
28.5 x 106 psi
196 GPa
Thermal Conductivity 212°F (100°C)
10.6 BTU/hr/ft2/ft/°F
18.3 W/m-°K
Melting Range
2560 – 2625°F
1404 – 1440°C
Electrical Resistivity
29.5 Microhm-in at 75°C
75 Microhm-cm at 24°C
Mean Coefficient of Thermal Expansion
| °F | °C | in/in °F | cm/cm °C |
| 70-800 | 21-427 | 6.3 x 10-6 | 11.3 x 10-6 |
Mechanical Properties
Room temperature properties (longitudinal direction)
Guaranteed values (ASTM A693 hot rolled plates)
Table 1
0.2% Offset | Strength | |||||
|---|---|---|---|---|---|---|
| (MPa) | ksi | (MPa) | ksi | % | ||
| Hardening 496 °C (925 °F) 4 h, air cooling | Min. | 1070 | 155 | 1170 | 170 | 8 |
| Typ. | 1207 | 175 | 1310 | 190 | 14 | |
| Hardening 593 °C (1100°F) 4 h, air cooling | Min. | 790 | 115 | 965 | 140 | 10 |
| Typ. | 931 | 135 | 1034 | 150 | 17 | |
Fabrication Data
Alloy 17-4PH can be easily welded and processed by standard shop fabrication practices. It is magnetic.
Heat Treatment
Alloy 17-4PH is provided in the solution-annealed condition (Condition A). Mechanical properties may be altered by subsequent age hardening treatments. These aging treatments are referred to as Conditions H900, H1025, H1075, H1150, H1150M and H1150D. The processes are outlined in Table 2 below. The resultant mechanical properties appear above in Table 1
Table 2
| CONDITION | Temperature °F | Time, h | Quench |
|---|---|---|---|
| H900 | 900 | 4 | Air Cool |
| H1025 | 1025 | 4 | Air Cool |
| H1075 | 1075 | 4 | Air Cool |
| H1150 | 1150 | 4 | Air Cool |
| H1150M | 1400 for 2 h, air cool plus 1150 for 4 h, air cool | ||
| H1150D | 1400 for 2 h, air cool plus 1150 for 4 h, air cool | ||
Cold Forming
Alloy 17-4PH has limited cold forming properties. Cold forming can only be undertaken on plates in the fully annealed condition. Stress corrosion resistance is enhanced by re-aging at the precipitation hardening temperature after cold working.
Hot Forming
Heat uniformly at 1742 – 2192°F (950 – 1200°C). A full solution anneal, cooling lower than 76°F (25°C) and aging at the required temperature must occur after hot forming. The post forming heat treatment should be a function of the desired mechanical properties.
Machining
Alloy 17-4PH can be machined in both the solution treated and precipitation hardened conditions. Machining characteristics may vary according to the hardness of the metal. High speed tools are acceptable, but carbide tools are preferred. Standard lubrication should be used. Dimensional changes as a result heat treatment should be taken into account if very stringent tolerances are required.
Cutting
Thermal cutting operations such as plasma cutting should be avoided. Mechanical cutting operations such as bandsaw, abrasive waterjet, shearing and machining are preferred.
Welding
Alloy 17-4PH can be readily welded by most standard processes including SMAW, GTAW, PAW and GMAW.
Alloy 17-4PH Stainless Steel – Frequently Asked Questions
1. What is Alloy 17-4PH stainless steel?
Alloy 17-4PH (UNS S17400) is a precipitation hardening martensitic stainless steel containing chromium, nickel, copper, and niobium. It delivers a unique combination of high strength, hardness, and moderate corrosion resistance. It is commonly supplied in the solution-annealed condition (Condition A) and strengthened through heat treatment.
2. What are typical applications for Alloy 17-4PH?
This high-strength alloy is used across a range of industries, including:
• Aerospace structural components
• Biomedical tools and hand instruments
• Nuclear waste containment
• Pulp and paper processing equipment
• Oil and gas platforms and foils
• Mechanical components and gate valves
• Food processing systems
3. How does 17-4PH perform in corrosive environments?
Its corrosion resistance is similar to 304 stainless steel in most environments and significantly better than 400-series martensitic grades. However, it is not ideal for prolonged exposure to stagnant seawater or highly chlorinated environments. In chloride and H₂S environments, higher aging temperatures (preferably 1094°F / 590°C) are recommended.
4. Can Alloy 17-4PH be heat treated?
Yes. Alloy 17-4PH is supplied in the solution-annealed Condition A and can be further heat treated through age hardening to modify mechanical properties. Common treatments include:
• H900 – 900°F (482°C) for 4 hours, air cooled (highest strength)
• H1025, H1075, H1150 – higher aging temperatures with varying strength and toughness
• H1150M, H1150D – involve multi-step aging cycles
5. What are the mechanical properties of Alloy 17-4PH stainless steel?
Mechanical properties vary based on the heat treatment condition. In the H900 condition, 17-4PH achieves a minimum yield strength of 155 ksi (1,070 MPa) and tensile strength of 170 ksi (1,170 MPa), with a minimum elongation of 8%. In the H1150 condition, it has a lower yield strength of 115 ksi (790 MPa), tensile strength of 140 ksi (965 MPa), and improved ductility with minimum elongation of 10%. Typical values in these conditions may be even higher depending on processing.
6. What are the physical properties of 17-4PH?
• Density: 0.280 lbs/in³ (7.75 g/cm³)
• Specific Heat: 0.11 BTU/lb-°F
• Modulus of Elasticity: 28.5 × 10⁶ psi (196 GPa)
• Thermal Conductivity at 212°F: 10.6 BTU/hr/ft²/ft/°F
• Electrical Resistivity: 29.5 Microhm-in
• Coefficient of Thermal Expansion (70–800°F): 6.3 × 10⁻⁶ in/in-°F
7. Is Alloy 17-4PH magnetic?
Yes. This grade is magnetic in all conditions.
8. Can 17-4PH be cold or hot formed?
Cold forming is limited and should only be done in the annealed condition. Hot forming should be performed at 1742–2192°F (950–1200°C), followed by solution annealing and aging for final mechanical properties.
9. Is 17-4PH machinable?
Yes. It machines well in both solution-annealed and precipitation-hardened conditions. Carbide tooling is preferred. Dimensional allowances should be made for post-machining heat treatment if required.
10. What are the welding guidelines for Alloy 17-4PH?
It can be welded using standard processes such as GTAW, SMAW, and GMAW. Post-weld heat treatment is often required to achieve optimal strength and corrosion resistance.
11. What specifications apply to 17-4PH stainless steel?
• ASTM A693
• ASME SA693
• AMS 5604
12. What thicknesses of Alloy 17-4PH plate does Sandmeyer Steel stock?
Sandmeyer Steel stocks Alloy 17-4PH plate in thicknesses from 3/16″ (4.8 mm) through 4″ (101.6 mm) in the annealed (Condition A) state.