17-4 PH Stainless Steel: Properties and Applications
Published on January 15, 2025 Author: TangShan Polarislink Advanced Materials Technology Co.,Ltd.
What is 17-4 PH Stainless Steel?
17-4 PH stainless steel is a precipitation-hardening martensitic stainless steel with excellent strength, hardness, and corrosion resistance. Its composition includes approximately 17% chromium, 4% nickel, and small amounts of copper and niobium, which endow it with unique properties. This alloy can obtain various mechanical properties through heat treatment, so it can be highly customized according to specific applications.
This grade is widely used in aerospace, chemical processing, and marine environments, as well as applications requiring strength and corrosion resistance such as fasteners, gears, and high-performance components. Its precipitation hardening ability can maintain good corrosion resistance in most environments while providing excellent strength.
17-4 PH stainless steel can also be machined and welded through appropriate technologies, but caution must be exercised during processing to maintain its ideal properties. Combining high strength and corrosion resistance, 17-4 PH stainless steel is an excellent choice for hig
h-demand engineering and industrial applications.
17-4 Stainless Steel Cast Products
Cast components are made of 17-4 PH stainless steel.
17-4PH Stainless Steel Specification Standards
| Specification Standard | Name | Description |
| American Society for Testing and Materials (ASTM) | ASTM A693 Grade 630 | 17-4PH alloy has the characteristics of high strength, high hardness, and corrosion resistance. After heat treatment, the mechanical properties of the product are improved. The compressive strength can reach 1100 – 1300 MPa (160 – 190 ksi). It has good corrosion resistance to the atmosphere and dilute acids or salts. |
| GB/T | GB/T 05Cr17Ni4Cu4Nb | |
| EN | X5CrNiCuNb16 – 4 | |
| JIS | JIS SUS630 | |
| DIN Standard | DIN X5CrNiCuNb17 – 4 – 4 |
Chemical Composition of 17-4 PH Stainless Steel
| Grade | C | Mn | Si | P | S | Cr | Cu | Ni | Nb + Ta |
| 17-4PH | ≤0.07% | ≤1.00% | ≤1.00% | ≤0.04% | ≤0.03% | 15.5% – 17.5% | 3.0% – 5.0% | 3.0% – 5.0% | 0.15% – 0.45% |
Mechanical Properties of 17-4 PH Stainless Steel
In the solution heat treatment state, the hardness of 17-4PH is HRC 39 or lower. After heat treatment, its properties are significantly improved. For example, the tensile strength can reach about 1000-1100 MPa, the yield strength is about 965-1000 MPa, and the hardness can exceed HRC40.
17-4PH stainless steel round bars have significant advantages in hardness. After solution treatment and aging treatment, excellent hardness levels can be achieved. Usually, it can reach HRC40 and above. It also has obvious advantages in strength. It achieves a good balance between strength and toughness. The yield strength and tensile strength are higher, so it can bear greater loads and stresses.
Corrosion Resistance of 17-4 PH Stainless Steel
17-4PH is a precipitation-hardening martensitic stainless steel with unique corrosion resistance. Compared with 304 stainless steel, 17-4PH has comparable corrosion resistance in most environments. In fields such as chemical processing and food processing, the corrosion resistance of 17-4PH in certain applications can be comparable to that of 304L. After precipitation hardening, 17-4PH can obtain higher strength while maintaining better corrosion resistance. Its chemical composition plays a key role in corrosion resistance. The combination of high strength and good corrosion resistance is fully reflected in applications such as valve parts. However, in practical applications, 17-4PH should be reasonably selected and used according to the specific service environment and requirements to ensure the full exertion of its performance and the extension of its service life.
Case Study
A railway equipment manufacturer faced corrosion and strength issues when using traditional materials to manufacture new turnout components under harsh climatic conditions. TangShan Polarislink Advanced Materials Technology Co.,Ltd. recommended 17-4PH stainless steel to them and formulated a customized heat treatment strategy: H1025 for turnout rails to balance strength and toughness; H900 for fasteners to ensure high strength and anti-loosening performance.
By optimizing smelting, heat treatment, and applying proprietary surface treatment to enhance wear resistance, the upgraded components performed excellently in field tests in cold northern and humid coastal areas. This solution extended the service life, reduced maintenance frequency, and proved the value of 17-4PH stainless steel as a high-performance and cost-effective material in critical railway applications.
Tangshan Polarislink Advanced Materials Technology Co., Ltd. was established in 1996 and is located in Tangshan, Hebei Province, China. The company is a source manufacturer specializing in wear parts for mining machinery. Relying on its own core factory, the company has been deeply engaged in heavy manufacturing for nearly 30 years, forming a stable industrial foundation centered on manufacturing capability.
The main products include high manganese steel hammers, jaw plates, bushings, mantles, impact plates, high chromium blow bars, cast steel bushings （Mn13/Mn13Cr2，Mn18/Mn18cr2，Mn22/Mn22Cr2） and various other wear-resistant castings, which are widely used in mining crushing, sand and aggregate production, cement and building materials industries. The company is certified by CE and ISO9001, and is capable of long-term batch supply and high-standard customized delivery.
The manufacturing base covers about 100,000 square meters, with a building area of 36,000 square meters, and is equipped with a complete production system including melting, casting, machining, heat treatment and final inspection. With 11 medium-frequency furnaces of 2–10 tons, 2 refining furnaces of 25 tons, 18 heat-treatment furnaces and more than 30 large CNC machines, the annual comprehensive capacity exceeds 50,000 tons, enabling stable production of large, high-strength and high-wear-resistant industrial castings.Official website address:https://www.polarislink.net/
