Precipitation Hardened Alloys
Available in strip and wire
Manufacturers no longer need to compromise when looking for material properties to satisfy conflicting manufacturing and end use requirements. Precipitation Hardening Stainless Steels offer the optimum combination of properties commonly found in the Austenitic and Martensitic Stainless Steel grades. Like Martensitic alloys, these grades can be strengthened through heat treatment, but have the added advantage of superior corrosion resistance that is most similar to that seen in Austenitic grades.
Available Precipitation Hardening Stainless Steel Grades
What are the benefits of using Precipitation Hardening Stainless Steel Alloys?
High work hardening rates
Very high strengths
Better corrosion resistance compared to martensitics
What are the disadvantages of using Precipitation Hardening Stainless Steel Alloys?
Limited availability and lower corrosion resistance, formability and weldability compared to austenitics
Precipitation Hardening Alloys are one of the five groups of the Stainless Steel family. Stainless Steel Alloys within this group offer the optimum combination of properties found in the Austenitic and Martensitic grades of Stainless Steel.
Sometimes known as Aged Hardened Alloys, these alloys possess a higher carbon content in comparison to the Ferritic Stainless Steel group. As a result of higher carbon content, these alloys can be hardened using air, oil or water cooling, improving their strength. In fact, some grades can offer strength properties between three and four times higher than Austenitic Stainless Steel grades, such as 1.4301, 1.4401 and 1.4436.
Other key alloying elements of precipitation hardened alloys include aluminium, titanium, niobium and molybdenum, either in combination or on their own. Consequently, this group of stainless steel alloys offers manufacturers many superior properties by combining high work hardening rates with very high strengths, superior fatigue properties, good corrosion resistance and good formability. Equally, there is minimum distortion when these alloys are heat treated, making them ideal for multiple applications.
There are three further subdivisions of Precipitation Hardening Stainless Steel, low carbon martensitic, semi-austenitic and austenitic. The most common alloy grade 17/4PH falls into the Martensitic category. Another common grade is 17-7PH, a austenitic-martensitic type alloy, which is ideal for aerospace applications, spring manufacturing and surgical instruments.
| PRECIPITATION HARDENING STAINLESS STEEL CHEMICAL COMPOSITION | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | TYPICAL CHEMICAL COMPOSITION % | ||||||||||||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | C | Si | Mn | P | S | Cr | Mo | Ni | N | Cu | Other |
| 1.4542 | X5CrNiCuNb16-4 | - | - | 17-4PH | 0.07 | 0.7 | 1.5 | 0.04 | 0.015 | 15.0 - 17.0 | 0.6 | 3.0 - 5.0 | - | 3.0 - 5.0 | Nb: 5 x C - 0.45 |
| 1.4568 | X7 Cr Ni Al 17-7 | 301S81 | 631 | 17-7PH AMS5678 | 0.09 | 0.7 | 1.0 | 0.04 | 0.015 | 16.0 - 18.0 | - | 6.5 - 7.8 | Strip: - Wire: 0.015 | - | Al: 0.7 - 1.5 |
| PRECIPITATION HARDENING STAINLESS STEEL STRIP MECHANICAL PROPERTIES ANNEALED STAINLESS STEEL | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | Proof Strength 0.2% Min (N/mm2) | Tensile Strength | Elong. % Min. (50mm Gauge Length) | Hardness Max (VPN) | Surface Finish | ||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | |||||
| 1.4542 | X5CrNiCuNb16-4 | - | - | 17-4PH | 700 - 1150 | 900 - 1270 | 3 - 6 | 380 | 2R |
| 1.4568 | X7 Cr Ni Al 17-7 | 301S81 | 631 | 17-7PH AMS5678 | Available on request | max. 850 | Available on request | 268 | 2R |
| Mechanical Properties - Precipitation Hardening Stainless Steel (17/7 PH/ 1.4568 / X7 Cr Ni Al 17-7 / 301S81) | ||
| Tensile Strength in the Cold Drawn and Post Heat Treatment Condition | ||
| Nominal Diameter (mm) | Min Tensile Strength Cold drawn (Condition C). (N/mm²) | Expected Min Tensile for Precipitation Hardened (N/mm²) |
| less than 0.20 | 1975 | 2275 |
| 0.20 – 0.30 | 1950 | 2250 |
| 0.30 – 0.40 | 1925 | 2225 |
| 0.40 – 0.50 | 1900 | 2200 |
| 0.50 – 0.65 | 1850 | 2150 |
| 0.65 – 0.80 | 1825 | 2125 |
| 0.80 – 1.00 | 1800 | 2100 |
| 1.00 – 1.25 | 1750 | 2050 |
| 1.25 – 1.50 | 1700 | 2000 |
| 1.50 – 1.75 | 1650 | 1950 |
| 1.75 – 2.00 | 1600 | 1900 |
| 2.00 – 2.50 | 1550 | 1850 |
| 2.50 – 3.00 | 1500 | 1800 |
| 3.00 – 3.50 | 1450 | 1750 |
| 3.50 – 4.25 | 1400 | 1700 |
| 4.25 – 5.00 | 1350 | 1650 |
| 5.00 – 6.00 | 1300 | 1550 |
| 6.00 – 7.00 | 1250 | 1500 |
| 7.00 – 8.50 | 1250 | 1500 |
| 8.50 – 10.00 | 1250 | 1500 |
| Note : The maximum tensile strength shall be the minimum value plus 15%. | ||
| MATERIAL FEATURES AND APPLICATIONS OF PRECIPITATION HARDENING STAINLESS STEEL | |||||||
|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | Key Features | Key Markets | Applications | ||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | |||
| 1.4542 | X5CrNiCuNb16-4 | - | - | 17-4PH | 17-4PH (1.4542) is the most commonly used Precipitation Hardening grade of Stainless Steel. This alloy offers good mechanical properties at temperatures up to 316°C (600°F), with a good combination of corrosion resistance and high strength. Its corrosion resistance is very similar to the Austenitic Stainless Steel grade 304. (1.4301), however it is significantly more resistant to stress corrosion cracking. It is susceptible to crevice corrosion in stagnant sea water. | Aerospace, Marine, Sport & Leisure, Mechanical, Pulp & Paper Industry, Chemical Processing, Petrochemical, Food processing | pump components, mechanical parts, golf clubs, seals, surgical parts, aerospace components, petrochemical parts |
| 1.4568 | X7 Cr Ni Al 17-7 | 301S81 | 631 | 17-7PH AMS5678 | 17-7 PH (1.4568) is a Stainless Steel alloy which is considered austenitic in the annealed condition, but martensitic in the hardened condition. This alloy offers a combination of high strength and hardness, excellent fatigue properties and minimum distortion upon heat treatment. It has good strength and formability and is comparable to Austenitic Grade 301 (1.4310) . Corrosion resistance is generally higher than the Martensitic Stainless Steels and 17-4PH, but is lower than 304 (1.4301). This grade can be heat treated after forming to further enhance the mechanical properties. | Aerospace, Medical, Springs & Pressings | bellows, honeycomb, high temperature fasteners, springs, diaphragms, strain gauges, clips, washers, surgical parts and blades |
Stripe Processing
All data is provided for informational purposes only. In no event will Precision Metals EU and its partners, be liable with respect to any action taken by any third party arising from using the information taken from our online or printed sources. Chemical and Mechanical Properties should not be construed as maximum or minimum values for specifications, nor should the information be used to assess suitability for a particular use or application. The information and data provided are deemed to be accurate to the best of our knowledge and may be revised anytime without notice, and assume no duty to update.