17-4 PH Stainless Steel Flanges
17-4 PH Stainless Steel Flanges (UNS S17400)
17-4 PH Stainless Steel (UNS S17400) is a precipitation-hardening martensitic stainless steel that delivers an exceptional combination of high strength, hardness, corrosion resistance, and toughness. This alloy achieves superior mechanical properties through heat treatment, making it highly versatile for both high-pressure and high-temperature applications.
At Emirerri Steel, we are a leading manufacturer and exporter of 17-4 PH stainless steel flanges, offering precision-forged components that perform reliably in aerospace, chemical processing, power generation, and marine environments.
Key Features
Exceptionally high tensile and yield strength
Excellent corrosion resistance comparable to 304 stainless steel
Maintains strength up to 600°F (315°C)
Good oxidation and scaling resistance
Can be heat-treated to multiple strength levels (H900–H1150)
Excellent dimensional stability and machinability
Suitable for heavy-duty and high-pressure applications
Type of 17-4 PH Stainless Steel Flanges
Specification
| Specification | Details |
|---|---|
| Standard | ASTM A182 / ASME SA182 |
| Grade | 17-4 PH |
| UNS Number | S17400 |
| Material Type | Precipitation-Hardening Martensitic Stainless Steel |
| Manufacturing Process | Forged / Rolled |
| Forms | Flanges, Fittings, Valves, Shafts, Forged Components |
| Pressure Class | 150#, 300#, 600#, 900#, 1500#, 2500# |
| Size Range | ½” to 48” (DN15 – DN1200) |
| Dimensions | ASME B16.5, B16.47, DIN, EN, JIS, GOST |
Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| UNS | S17400 |
| EN | X5CrNiCuNb16-4 |
| DIN | 1.4542 |
| JIS | SUS630 |
| AFNOR | Z6CNU17-04 |
| BS | 630S17 |
Available Sizes
Flanges: ½” NB to 48” NB
Forged Fittings: ⅛” to 4”
Custom dimensions available on request
Chemical Composition
| Element | Percentage (%) |
|---|---|
| Carbon (C) | 0.07 max |
| Manganese (Mn) | 1.00 max |
| Silicon (Si) | 1.00 max |
| Phosphorus (P) | 0.040 max |
| Sulfur (S) | 0.030 max |
| Chromium (Cr) | 15.00 – 17.50 |
| Nickel (Ni) | 3.00 – 5.00 |
| Copper (Cu) | 3.00 – 5.00 |
| Niobium + Tantalum (Nb + Ta) | 0.15 – 0.45 |
| Iron (Fe) | Balance |
Mechanical Properties
(in H900 Condition)
| Property | Unit | Value |
|---|---|---|
| Tensile Strength | MPa | 1310 min |
| Yield Strength (0.2% Proof) | MPa | 1170 min |
| Elongation | % | 10 min |
| Reduction of Area | % | 40 min |
| Hardness | HRC | 44 min |
| Impact Toughness | J | 35 (typical) |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | g/cm³ | 7.75 |
| Melting Point | °C | 1400 – 1440 |
| Thermal Conductivity | W/m·K | 18.4 |
| Electrical Resistivity | µΩ·m | 0.80 |
| Modulus of Elasticity | GPa | 200 |
| Specific Heat | J/kg·K | 500 |
Corrosion Resistance
17-4 PH Stainless Steel provides excellent resistance to atmospheric corrosion, dilute acids, and marine environments. Its corrosion performance is similar to Type 304 stainless steel, making it suitable for chemical, food processing, and marine applications. However, prolonged exposure to temperatures above 600°F (315°C) may reduce its corrosion resistance.
Heat Resistance
The alloy maintains high mechanical strength and hardness up to 600°F (315°C) and offers good oxidation resistance in intermittent exposure up to 870°C (1600°F). This makes it suitable for high-stress, high-temperature applications such as turbine blades, shafts, and pressure vessels.
Heat Treatment
Solution Treatment (Condition A): Heat to 1040°C (1900°F), air cool.
Aging Treatments:
H900: 482°C (900°F) – 1 hour, air cool.
H1025: 552°C (1025°F) – 4 hours, air cool.
H1075: 580°C (1075°F) – 4 hours, air cool.
H1150: 620°C (1150°F) – 4 hours, air cool.
Each condition provides a distinct combination of strength and toughness depending on application needs.
Welding
17-4 PH can be welded using TIG, MIG, and shielded metal arc welding techniques. Preheating is not required, but post-weld aging treatment is recommended to restore mechanical properties. Use matching filler metals such as AWS ER630 for optimum results.
Fabrication
17-4 PH stainless steel is easily machinable in solution-annealed condition. It can be forged between 1150°C and 950°C and must be air-cooled after hot working. The alloy exhibits excellent dimensional stability and minimal distortion during heat treatment or machining.
Applications
Aerospace Components (shafts, turbine parts, fasteners)
Chemical and Petrochemical Equipment
Pulp and Paper Industry
Marine and Offshore Structures
Pump and Valve Parts
Pressure Vessels and Heat Exchangers
Food Processing Equipment
Power Generation Systems