17-4 PH stainless steel is a precipitation-hardening stainless steel containing high concentrations of chromium, nickel and copper characterized by good mechanical properties, corrosion resistance and resistance to thermal expansion. In addition, 17-4PH stainless steel has excellent weldability and grinding properties and is suitable for a wide range of machining and fabrication processes.
17-4 PH is the most widely used precipitation-hardening stainless steel. This is due to its low cost and strength compared to other materials,17-4 PH is favored for its high strength, good corrosion resistance and good properties up to 600 degrees F. 17-4 PH is also known as 630 stainless steel.
Ph 17-7 Stainless Steel Composition
- Carbon (C): ≤ 0.07%
- Silicon (Si): ≤1.00%
- Manganese (Mn): ≤1.00%
- Phosphorus (P): ≤0.04%
- Sulphur (S): ≤0.03%
- Nickel (Ni): 3.0~5.0%
- Chromium (Cr): 15.0～17.0%
- Copper (Cu): 3.00 ~ 5.00%
- Columbium + tantalum: 0.15–0.45%
17-4 PH Stainless Steel Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 170000 psi, max |
| Yield Strength | 140000 psi, max |
| Elongation | 10%, min |
| Hardness, Rockwell C | 38, max |
17-7 PH Stainless Steel Specifications
- ASTM A 693 Standard Specification for Precipitation-Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip
- ASTM A705/A705M- standard Specification for Age-Hardening Stainless Steel Forgings
- ASTM A313/A313M Standard Specification for Stainless Steel Spring Wire
- ASTM A564/A564M Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes
- ASTM A579/A579M Standard Specification for Superstrength Alloy Steel Forgings
- ASTM A705/A705M standard Specification for Age-Hardening Stainless Steel Forgings
AMS Specifications
| AMS | Alloy | UNS | Shape |
|---|---|---|---|
| AMS 5604 Plate | 17-4PH | S17400 | Plate |
| AMS 5604 Sheet | 17-4PH | S17400 | Sheet |
| AMS 5604 Strip | 17-4PH | S17400 | Strip |
| AMS 5643 Bar | 17-4PH | S17400 | Bar |
| AMS 5643 Forging | 17-4PH | S17400 | Forging |
| AMS 5643 Ring | 17-4PH | S17400 | Ring |
| AMS 5643 Tubing | 17-4PH | S17400 | Tubing |
| AMS 5643 Wire | 17-4PH | S17400 | Wire |
17-4 PH Stainless Steel Equivalent
- GB: 05Cr17Ni4Cu4Nb
- UNS: S17400
- DIN: W.Nr.1.4542
- AISI 630
- JIS: SUS630
Ph 17-7 Stainless Steel Properties
- High strength and hardness: 17-4 stainless steel has high strength and hardness, and its compressive strength can reach up to 1300MPa after heat treatment.
- Good corrosion resistance: the material shows good corrosion resistance in a variety of environments, especially in temperatures up to 600 ° F (316 ° C) can still maintain excellent mechanical properties.
- Outstanding Toughness: Good toughness in both base metals and welds.
- Thermal Stability: Maintains high tensile strength and hardness at temperatures up to 316°C and excellent oxidation resistance at temperatures up to 593°C.
- Machinability and weldability: 17-4 stainless steel also offers excellent machinability and high weldability compared to traditional martensitic stainless steel.
Applications
- Aerospace: Used in the manufacture of engine parts, turbine blades, bolts and other critical components, this is due to its good resistance to high temperatures and corrosion.
- Marine field: Used in manufacturing anchor chains, ship bearings and propellers, etc., thanks to its good overall performance.
- Petrochemical field: Used in the petrochemical industry for the manufacture of pipelines, valves, pumps, tanks and other equipment, because it can maintain good mechanical properties at high temperatures and high pressures, a strong corrosive media environment.
- Medical equipment field: Used in the manufacture of artificial joints, surgical instruments and dental instruments.
- Automotive manufacturing field: Used in the manufacture of engine parts, suspension systems and exhaust systems.
- Food processing field: Used in the manufacture of food machinery, tanks and containers, etc., because it has good corrosion resistance in a variety of corrosive media.
- Offshore Floating Device Sector: Used in structural parts and connectors of offshore floating devices, such as offshore oil well platforms, offshore wind power generation equipment, etc., mainly due to its good corrosion resistance to seawater.
- Other fields: It can also be used in metal products, machinery manufacturing, rail transport, nuclear power, chemical equipment, edible machinery and so on .
17-4 Stainless Steel vs 304
Chemical Composition
17-4PH stainless steel contains a large amount of chromium and nickel, as well as a small amount of copper, titanium, vanadium and other elements, which makes it has excellent corrosion resistance and high-temperature strength. While 304 stainless steel contains 18% chromium and 8% nickel, while also containing small amounts of carbon, manganese, phosphorus, sulfur, iron and other elements. It can be seen that the chemical composition of 17-4PH stainless steel and 304 stainless steel has a big difference.
Physical Properties
17-4PH stainless steel has good corrosion resistance, heat resistance and high strength, and its hardness can reach 40-46 HRC. 304 stainless steel, although it has good corrosion resistance and toughness, but its strength and hardness are relatively low, and can not meet the needs of some special applications.
Corrosion Resistance
The corrosion resistance of 17-4PH stainless steel is comparable to that of 304 stainless steel and is generally superior to 400 series stainless steel. In warm chloride environments, both may experience pitting and crevice corrosion.
FAQ
17-4PH is a precipitation-hardening martensitic stainless steel containing copper and niobium/columbium elements, and it can be heat-treated to obtain a compressive strength of up to 1,100-1,300 MPa, but its corrosion resistance is comparable to that of 304 and 430, and it can’t be used at temperatures higher than 300°C or very low temperatures. While 316 is an austenitic stainless steel with high molybdenum and chromium, it has excellent resistance to pitting corrosion and is suitable for environments containing chloride ions.
17-4ph stainless steel will rust under certain conditions.17-4ph stainless steel has the ability of stainless steel, but this ability will be affected by a variety of factors, including chemical composition, processing state, use conditions and the type of environmental media. The rust resistance of stainless steel depends mainly on the formation of a thin and stable layer of chromium-rich oxide film on its surface, which prevents the penetration and oxidation of oxygen atoms, thus obtaining the ability to resist rust and corrosion. However, if this film is damaged, oxygen atoms will penetrate into the metal surface and form loose iron oxide, leading to rusting of the metal surface.
17-4 PH stainless steel can be welded and has good welding performance.17-4 PH stainless steel can be welded via various welding methods, including argon arc welding, electric arc welding, and laser welding. In the welding process, the appropriate welding process and welding material selection can ensure the strength and corrosion resistance of the weld seam.