Stainless Steel 1.4515-ST (Solution annealed)
Heat-treated state · default condition
EN 1.4515 · UNS J93373 · ASTM CD4MCuN
The standard delivery condition for all pressure-retaining and corrosion service; restores the ferrite/austenite balance and dissolves intermetallics.
Values for the ST condition
Other 1.4515 tempers and conditions
1.4515 is listed in 4 conditions; see the grade overview at 1.4515.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Only an intermediate stage before solution annealing — as-cast material has intermetallic/nitride precipitation, low toughness and degraded corrosion resistance, and is not supplied for service. | 500 | 700 | 10 | 25 HRC | 2.2 % IACS |
As-welded deposit | Condition of production weld repairs made with matching 25Cr duplex filler when a full re-solution treatment is not practical; expect reduced toughness and local corrosion performance. | 520 | 720 | 18 | 23 HRC | 2.2 % IACS |
STDefaultThis page Solution annealed | The standard delivery condition for all pressure-retaining and corrosion service; restores the ferrite/austenite balance and dissolves intermetallics. | 540 | 740 | 25 | 22 HRC | — |
Hot isostatically pressed then solution annealed and quenched | Choose for thick-wall pump/valve castings where internal porosity must be eliminated for radiographic acceptance and higher ductility/toughness. | 555 | 770 | 30 | 22 HRC | 2.2 % IACS |
What is 1.4515-ST?
1.4515-ST is 1.4515 heat treated to ST — the standard delivery condition for all pressure-retaining and corrosion service; restores the ferrite/austenite balance and dissolves intermetallics. 1.4515-ST has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 82% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi). 1.4515-ST has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Advantages
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
- High strength — 540 MPa (78.3 ksi), better than 82% of stainless steel grades
Limitations
- Limited service temperature — 280°C (536 °F), worse than 96% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Low fracture toughness — 90 MPa·√m (81.9 ksi·√in), worse than 75% of stainless steel grades
1.4515-ST properties
Typical room-temperature values for 1.4515-ST; 10 are specific to this condition. Other listed values are 1.4515 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4515-ST has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical17
1.4515-ST has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 82% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4515-ST is rated for continuous service to 280°C (536 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), better than 58% of stainless steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
1.4515-ST conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 84% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4515-ST takes about 53 MJ of energy and emits 5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 80%.
Manufacturability8
1.4515-ST's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability good (60/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4515-ST
Is 1.4515 easy to machine?
Machine like a 25Cr duplex: rigid setups, positive-rake coated carbide, ~40–70 m/min cutting speed, heavy feeds to cut under the work-hardened layer and copious flood coolant.
Can 1.4515 be welded?
Weldable with matching 25Cr-Cu duplex (or ER2594/E2553) filler; control heat input and interpass ≤150 °C to keep 35–55 % ferrite, avoid autogenous welds, and re-solution anneal + water quench where full corrosion performance is required.
Can 1.4515 be formed, bent or molded?
Sand or investment cast with good fluidity; use generous risering and directional solidification, keep nitrogen in range, and always solution anneal ~1100–1150 °C followed by rapid water quench.
What surface finishes work on 1.4515?
Pickle and passivate (or electropolish) after heat treatment and grinding to restore the passive film; no anodising — shot blast/mechanical polish is acceptable for slurry surfaces.
1.4515 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow-carbon cast duplex | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.7 |
| MnASTM A890 Gr.1B allows up to 1.00 | ≤ 1 | 0.7 |
| PA890 allows 0.04 max | ≤ 0.04 | — |
| SA890 allows 0.04 max | ≤ 0.03 | — |
| Cr | 24.5 – 26.5 | 25.5 |
| Ni | 5.6 – 6.5 | 6 |
| Mo | 1.8 – 2.5 | 2.1 |
| Cuimproves sulphuric-acid resistance | 2.7 – 3.3 | 3 |
| Nstabilises austenite, raises PREN | 0.1 – 0.25 | 0.18 |
| Fe | balance | — |
1.4515-ST — frequently asked
What is 1.4515-ST used for?
1.4515-ST is typically used for pump impellers, valve trim, seawater handling equipment and desalination components. In short: high-strength cast duplex; sulfuric acid erosion resistance; copper-bearing CD4MCu development.
What is the yield strength of 1.4515-ST?
1.4515-ST has a typical yield strength of 540 MPa (78.3 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 82% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4515-ST easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Machine like a 25Cr duplex: rigid setups, positive-rake coated carbide, ~40–70 m/min cutting speed, heavy feeds to cut under the work-hardened layer and copious flood coolant.
Can 1.4515-ST be welded?
Yes — weldability is rated good (60/100). Weldable with matching 25Cr-Cu duplex (or ER2594/E2553) filler; control heat input and interpass ≤150 °C to keep 35–55 % ferrite, avoid autogenous welds, and re-solution anneal + water quench where full corrosion performance is required.
What surface finishes work on 1.4515-ST?
Pickle and passivate (or electropolish) after heat treatment and grinding to restore the passive film; no anodising — shot blast/mechanical polish is acceptable for slurry surfaces.
Can 1.4515-ST be formed, bent or molded?
Sand or investment cast with good fluidity; use generous risering and directional solidification, keep nitrogen in range, and always solution anneal ~1100–1150 °C followed by rapid water quench.
What is the maximum service temperature of 1.4515-ST?
1.4515-ST is rated for continuous use to about 280°C (536 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4515-ST and 1.4515-AC?
ST is the default condition — the standard delivery condition for all pressure-retaining and corrosion service; restores the ferrite/austenite balance and dissolves intermetallics. AC: only an intermediate stage before solution annealing — as-cast material has intermetallic/nitride precipitation, low toughness and degraded corrosion resistance, and is not supplied for service. Yield strength is 540 MPa in ST versus 500 MPa in AC.
Sources
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A890/A890M — Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Grade 1B, CD4MCuN) — ASTM (2023)
- ASTM A995/A995M — Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for Pressure-Containing Parts — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast corrosion-resistant steels) — ASM International (1990)
- ASM Specialty Handbook: Stainless Steels (duplex cast alloys) — ASM International (1994)
- Duplex stainless casting grade datasheets (CD4MCuN / 1.4515) — stainless foundry producers (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.