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Stainless Steel 1.4515-AC (Spheroidize annealed)

Heat-treated state

EN 1.4515 · UNS J93373 · ASTM CD4MCuN

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.

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Values for the AC 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 datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
ACThis page
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.5007001025 HRC2.2 % 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.5207201823 HRC2.2 % IACS
STDefault
Solution annealed
The standard delivery condition for all pressure-retaining and corrosion service; restores the ferrite/austenite balance and dissolves intermetallics.5407402522 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.5557703022 HRC2.2 % IACS

What is 1.4515-AC?

1.4515-AC is 1.4515 heat treated to 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. 1.4515-AC has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 10% and the elastic modulus is 200 GPa (29 Msi). 1.4515-AC 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). ST is the default condition FabDigit quotes; AC is available on request or by drawing note.

Advantages

  • High strength — 500 MPa (72.5 ksi), better than 77% of stainless steel grades

Limitations

  • Limited service temperature — 150°C (302 °F), worse than 100% of stainless steel grades
  • Limited ductility — 10%, worse than 98% of stainless steel grades
  • Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 95% of stainless steel grades
  • Difficult to machine — 22/100, worse than 95% of stainless steel grades
  • Limited formability — 10/100, worse than 95% of stainless steel grades

1.4515-AC properties

Typical room-temperature values for 1.4515-AC; 23 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-AC 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).

Density7.75 g/cm³0.28 lb/in³
Melting Point (Solidus)1,400°C2,552 °F
Liquidus Temperature1,465°C2,669 °F

Mechanical17

1.4515-AC has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 10% and the elastic modulus is 200 GPa (29 Msi).

Elastic (Young's) Modulus200 GPa29 Msi
Shear Modulus77 GPa11.2 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)700 MPa102 ksi
Yield Strength (0.2% offset)500 MPa72.5 ksi
Elongation at Break10%
Reduction in Area15%
Compressive Strength515 MPa74.7 ksi
Shear Strength425 MPa61.6 ksi
Fatigue Strength (Endurance Limit)275 MPa39.9 ksi
Fracture Toughness (K_IC)45 MPa·√m41 ksi·√in
Charpy V-Notch Impact (RT)15 J11.1 ft·lbf
Hardness, Brinell255 HB
Hardness, Rockwell B100 HRB
Hardness, Rockwell C25 HRC
Hardness, Vickers268 HV

Thermal6

1.4515-AC is rated for continuous service to 150°C (302 °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).

Thermal Conductivity16 W/m·K9.2 BTU/hr·ft·°F
Specific Heat Capacity480 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)12 µm/m·K6.7 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)150°C302 °F
Min Service Temperature-50°C-58 °F

Electrical3

1.4515-AC conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.

Electrical Conductivity2.2 % IACS
Electrical Resistivity8×10⁻⁷ Ω·m31.5 µΩ·in
Magnetic Responseferromagnetic — duplex ferrite/austenite structure, roughly 40–50 % ferrite

Chemical & Environmental3

Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.

Galvanic Potential (seawater, vs SCE)-0.15 V
Corrosion ResistanceGood55/100
Chemical Resistance SummaryExcellent in dilute and concentrated sulphuric acid, phosphoric acid, chloride brines and seawater; copper addition markedly improves H₂SO₄ behaviour. Good resistance to pitting, crevice attack and chloride stress-corrosion cracking (PREN ≈ 38). Not for hot hydrochloric acid, hydrofluoric acid or strongly reducing halide media; avoid prolonged exposure above 300 °C.

Sustainability4

Producing a kilogram of 1.4515-AC takes about 53 MJ of energy and emits 5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 80%.

Embodied Energy (primary production)53 MJ/kg22,786 BTU/lb
Embodied Carbon (primary production)5 kg CO₂/kg
Embodied Water200 L/kg24 gal/lb
Typical Recycled Content80%

Manufacturability8

1.4515-AC's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability fair (45/100); formability not recommended (10/100).

MachinabilityPoor22/100
Machinability Rating (AISI 1212 = 100 %)20%
WeldabilityFair45/100
Formability (cold)Not recommended10/100
CastabilityGood65/100
Brazeability / SolderabilityPoor30/100
PolishabilityGood65/100
Anodizing Responsen/a — stainless steel; use pickling/passivation or electropolishing instead

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 1.4515-AC

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.

ElementSpec limit (wt %)Nominal
Clow-carbon cast duplex≤ 0.030.02
Si≤ 10.7
MnASTM A890 Gr.1B allows up to 1.00≤ 10.7
PA890 allows 0.04 max≤ 0.04—
SA890 allows 0.04 max≤ 0.03—
Cr24.5 – 26.525.5
Ni5.6 – 6.56
Mo1.8 – 2.52.1
Cuimproves sulphuric-acid resistance2.7 – 3.33
Nstabilises austenite, raises PREN0.1 – 0.250.18
Febalance—

1.4515-AC — frequently asked

What is 1.4515-AC used for?

1.4515-AC 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-AC?

1.4515-AC has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 77% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.

Is 1.4515-AC easy to machine?

Not especially — machinability is rated poor (22/100, worse than 95% 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-AC be welded?

With care — weldability is rated fair (45/100). 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-AC?

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-AC 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-AC?

1.4515-AC is rated for continuous use to about 150°C (302 °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

  1. EN 10283 — Corrosion resistant steel castings — CEN (2010)
  2. ASTM A890/A890M — Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Grade 1B, CD4MCuN) — ASTM (2023)
  3. ASTM A995/A995M — Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for Pressure-Containing Parts — ASTM (2020)
  4. ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast corrosion-resistant steels) — ASM International (1990)
  5. ASM Specialty Handbook: Stainless Steels (duplex cast alloys) — ASM International (1994)
  6. 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.