1.4545 Forgings (15-5 PH / UNS S15500): Rings, Flanges, Shafts and Bars

EN 1.4545, X5CrNiCu15-5, UNS S15500, ASTM Type XM-12, AMS 5659. Open-die forged and ring-rolled to your drawing.

• EN number 1.4545 (X5CrNiCu15-5)
• Equivalents 15-5 PH, S15500, XM-12
• Type Precipitation-hardening martensitic stainless
• Max tensile (H900) 1310 MPa / 190 ksi min
• Max hardness (H900) 40 HRC / 388 HBW min
• Melting route EAF + LF + VOD + ESR
• Conditions offered A, H900 to H1150M
• Certification EN 10204 3.1 / 3.2

What 1.4545 (15-5 PH) is, and why it is forged

1.4545 belongs to the copper-hardening group of stainless steels. Chromium and nickel give it corrosion resistance close to Type 304 and well above the plain martensitic grades 410, 420 and 431. The copper is what makes the alloy practical to work with. After solution treatment the material is soft enough to machine. A single low-temperature ageing step then precipitates a copper-rich phase that lifts strength by several hundred megapascals, with no quench, very little distortion and no scaling.

The grade was developed as a cleaner version of 17-4 PH. Chromium and nickel are balanced so that very little delta ferrite forms during solidification and hot work. Delta ferrite is what costs 17-4 PH its toughness across the grain flow in thick sections. Removing it matters to a forging shop. A ring with a 600 mm wall, or a disc a metre across, can be qualified in the transverse direction and not only along the bar axis.

For that reason 1.4545 is normally bought as forged stock rather than rolled plate when the part is large, highly stressed or pressure containing. Open-die forging and radial-axial ring rolling also put the grain flow along the part contour, which helps fatigue life in shafts, valve stems and ring-rolled races.

Equivalent designations and governing standards

State the governing specification and the required condition on your purchase order. The mechanical minimums differ between ASTM A564, ASTM A705 and AMS 5659, and between longitudinal and transverse test directions.

Chemical composition of 1.4545

Balance iron. Limits shown follow the EN basis for 1.4545. ASTM A564 Type XM-12 permits slightly higher phosphorus and sulphur and states niobium plus tantalum as 0.15 to 0.45 %. Where both standards are invoked we work to the tighter of the two. The actual heat analysis of your material is reported on the EN 10204 certificate.

Three elements do the work. Copper at 2.5 to 4.5 % forms the fine precipitates responsible for age hardening. Niobium, tied to five times the carbon content, locks up carbon as stable carbides so chromium stays in solution and corrosion resistance is not lost at the grain boundaries. Chromium and nickel together are balanced low enough in chromium equivalent to suppress delta ferrite, which is the metallurgical difference between this grade and 17-4 PH.

Mechanical properties by heat-treat condition

The figures below are the minimum requirements of ASTM A564 / A564M for Type XM-12 in sections up to 12 in. (300 mm). They are minimums rather than typical values, and material routinely exceeds them. Elongation and reduction of area are listed separately for the longitudinal (L) and transverse (T) test directions. Quoting a transverse elongation against a longitudinal strength is a common mistake in enquiries and it causes real problems at technical review.

L is longitudinal, the axis of the test specimen parallel to the direction of grain flow during forging. T is transverse, perpendicular to grain flow. Elongation is measured in 2 in. (50 mm) or 4D. Either Rockwell C or Brinell hardness is acceptable. Values reproduced from the requirements of ASTM A564 / A564M. Confirm against the current edition of the standard and your own purchase specification. Forgings ordered to ASTM A705 or AMS 5659 may carry different minimums.

Reading the table

Strength falls and toughness rises as the ageing temperature goes up. H900 doubles the room-temperature yield strength of an austenitic stainless but carries almost no Charpy requirement. H1150M gives up about 40 % of the tensile strength and returns eleven times the impact energy. H1025 and H1075 sit between the two, and they are the conditions most pressure-equipment and pump specifications land on.

Physical properties

Typical published values for guidance and design comparison. They are not specification requirements and are not guaranteed on certificate.

Heat treatment of 1.4545 forgings

Solution treatment, Condition A

Forgings are heated to 1040 ± 15 °C (1900 ± 25 °F), held, and cooled to below 32 °C (90 °F). The cool-down below room temperature matters. The martensite transformation has to be complete before ageing, or the part will not respond uniformly. In Condition A the material is machinable and can be supplied that way if you intend to age after machining.

Age hardening

Ageing temperatures are the suggested treatments of ASTM A564 and may be varied within the standard to hit the required tensile properties. We record the actual cycle, furnace charts and hardness survey on the certificate.

Plan for one dimensional effect. 1.4545 shrinks slightly on ageing, in the order of 0.05 % for the lower-temperature conditions. On close-tolerance machined forgings we either age before finish machining, or agree a growth allowance with you in advance.

1.4545 (15-5 PH) compared with 1.4542 (17-4 PH)

These two grades are asked about together more than any other pair in the precipitation-hardening family. The choice usually comes down to section size.

The two grades reach the same strength. If your part is a 60 mm shaft there is little reason to pay for 15-5 PH. If it is a 2 m ring or a 400 mm-thick block that has to pass transverse tensile and Charpy testing, 15-5 PH is the grade that will pass. We forge both. See our 17-4 PH (1.4542) forgings page for that alternative.

Forged product forms and size ranges

Machining allowance, forging reduction ratio and test-prolongation locations are agreed at order stage. Send a drawing or a sketch with dimensions, the governing specification and the required condition, and we will confirm feasibility and weight.

How we manufacture 1.4545 forgings

1. Melting and remelting EAF, ladle furnace and VOD, then ESR remelting to control segregation and inclusion content. VAR on request for aerospace orders.
2. Ingot conditioning Surface inspection and grinding, then heating to 1065 to 1205 °C.
3. Open-die forging Upsetting and drawing on hydraulic press to the agreed reduction ratio, finished above 980 °C.
4. Ring rolling Punching and expansion on a radial-axial mill for seamless rings, giving circumferential grain flow.
5. Solution treatment 1040 ± 15 °C, cooled below 32 °C, giving Condition A.
6. Age hardening To the ordered condition, H900 through H1150M, with recorded furnace charts.
7. Machining Rough or finish machining to drawing: CNC turning, boring, drilling, milling.
8. Testing and NDE Chemistry, tensile, impact, hardness, ultrasonic and surface examination.
9. Certification and packing Marking, EN 10204 3.1 or 3.2 certificate, preservation, export packing.

Testing, non-destructive examination and certification

Where 1.4545 forgings are used

Machining, welding and corrosion notes

Machining

Machinability in Condition A is close to the standard martensitic grades 410 and 431, and appreciably harder work than free-machining 303. Once aged to H900 the material is at 40 HRC minimum and turning, drilling and threading become slow and hard on tooling. The usual production sequence is to rough machine in Condition A, age, then finish machine. Where the part has to be machined after ageing, H1150M gives the best tool life.

Welding

1.4545 welds by conventional shielded fusion and resistance processes. AWS E630 or ER630 is the standard filler metal. Weld in Condition A or in an over-aged condition and re-age the assembly afterwards, so that weld metal, heat-affected zone and parent metal finish at the same strength. Preheat is not normally required. Post-weld solution treatment is preferred over a straight stress relief where the geometry allows it.

Corrosion behaviour

General corrosion resistance is similar to Type 304 and clearly better than 410, 420 or 431. The alloy handles atmospheric exposure, fresh water, dilute organic acids and many process chemicals. Like every high-strength martensitic PH grade, it becomes more susceptible to chloride stress-corrosion cracking as strength increases. For warm chloride service specify H1100, H1150 or H1150D rather than H900. It is not a substitute for a duplex or 6 Mo grade in seawater at temperature.

Frequently asked questions about 1.4545

Published by Jiangyin Jiangnan Metal Co., Ltd. Technical content reviewed against ASTM A564 / A564M and EN 10088-3. Last reviewed 23 September 2026. Data is given for guidance. The governing document for any order is the purchase specification and the EN 10204 certificate issued with the goods.