Stainless Steel CE3MN-AC (Spheroidize annealed)
Heat-treated state
ASTM CE3MN · UNS J93404 · EN 1.4417, GX2CrNiMoN25-7-3
Reference condition only: intermetallic and nitride precipitation from casting leaves low toughness and degraded corrosion resistance, so parts must be solution treated before service.
Values for the AC condition
Other CE3MN tempers and conditions
CE3MN is listed in 3 conditions; see the grade overview at CE3MN.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACThis page Spheroidize annealed | Reference condition only: intermetallic and nitride precipitation from casting leaves low toughness and degraded corrosion resistance, so parts must be solution treated before service. | 540 | 720 | 12 | 28 HRC | 2.1 % IACS |
SADefault Solution annealed ≥1120 °C and water quenched | The only condition in which the grade may be supplied to A890/A995 — pick it for all seawater, offshore and chemical castings. | 560 | 780 | 28 | 24 HRC | — |
hot isostatically pressed, then solution annealed and quenched | Choose for pressure-containing or fatigue-critical subsea castings where microporosity must be closed and toughness/soundness maximised. | 575 | 800 | 32 | 25 HRC | 2.2 % IACS |
What is CE3MN-AC?
CE3MN-AC is CE3MN heat treated to AC — reference condition only: intermetallic and nitride precipitation from casting leaves low toughness and degraded corrosion resistance, so parts must be solution treated before service. CE3MN-AC has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 82% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi). CE3MN-AC has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,350°C (2,462 °F). SA is the default condition FabDigit quotes; AC is available on request or by drawing note.
Advantages
- High strength — 540 MPa (78.3 ksi), better than 82% of stainless steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 100% of stainless steel grades
- Difficult to machine — 20/100, worse than 98% of stainless steel grades
- Limited ductility — 12%, worse than 95% of stainless steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 92% of stainless steel grades
- Limited formability — 15/100, worse than 91% of stainless steel grades
CE3MN-AC properties
Typical room-temperature values for CE3MN-AC; 22 are specific to this condition. Other listed values are CE3MN reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
CE3MN-AC has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Mechanical16
CE3MN-AC has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 82% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
CE3MN-AC is rated for continuous service to 200°C (392 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
CE3MN-AC conducts electricity at 2.1 % IACS, worse than 73% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 56% of stainless steel grades.
Sustainability4
Producing a kilogram of CE3MN-AC takes about 75 MJ of energy and emits 5.2 kg of CO₂ — more than 84% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
CE3MN-AC's machinability is poor (20/100, worse than 98% of stainless steel grades); weldability fair (40/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CE3MN-AC
Is CE3MN easy to machine?
Machine like super-duplex: rigid setup, sharp coated carbide, low-to-moderate speed with heavy positive feed and generous coolant to avoid work-hardened glazing.
Can CE3MN be welded?
GTAW/SMAW with 25.10.4L (2507-matching) filler, no preheat, interpass below ~150 °C and controlled heat input to keep ferrite 35-55 % and avoid sigma/nitride precipitation.
Can CE3MN be formed, bent or molded?
Cast product only — no cold forming; foundry must hold nitrogen recovery, feed heavy sections well and solution treat ≥1120 °C followed by rapid water quench.
What surface finishes work on CE3MN?
Grind/blast then citric or nitric passivation (ASTM A967); electropolishing gives best chloride performance, no anodising applicable.
CE3MN 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 |
|---|---|---|
| C | ≤ 0.03 | 0.02 |
| Mn | ≤ 1.5 | 0.8 |
| Si | ≤ 1 | 0.6 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Cr | 24 – 26 | 25 |
| Ni | 6 – 8 | 7 |
| Mo | 4 – 5 | 4.5 |
| Nkey austenite stabiliser; controls pitting resistance | 0.1 – 0.3 | 0.2 |
| Cu | ≤ 1.3 | 0.3 |
| Fe | balance | — |
CE3MN-AC — frequently asked
What is CE3MN-AC used for?
CE3MN-AC is typically used for subsea valve bodies, high-chloride pump casings, offshore manifolds and desalination castings. In short: cast equivalent of 2507; best chloride resistance here; highest strength cast duplex.
What is the yield strength of CE3MN-AC?
CE3MN-AC has a typical yield strength of 540 MPa (78.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 82% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is CE3MN-AC easy to machine?
Not especially — machinability is rated poor (20/100, worse than 98% of stainless steel grades). Machine like super-duplex: rigid setup, sharp coated carbide, low-to-moderate speed with heavy positive feed and generous coolant to avoid work-hardened glazing.
Can CE3MN-AC be welded?
With care — weldability is rated fair (40/100). GTAW/SMAW with 25.10.4L (2507-matching) filler, no preheat, interpass below ~150 °C and controlled heat input to keep ferrite 35-55 % and avoid sigma/nitride precipitation.
What surface finishes work on CE3MN-AC?
Grind/blast then citric or nitric passivation (ASTM A967); electropolishing gives best chloride performance, no anodising applicable.
Can CE3MN-AC be formed, bent or molded?
Cast product only — no cold forming; foundry must hold nitrogen recovery, feed heavy sections well and solution treat ≥1120 °C followed by rapid water quench.
What is the maximum service temperature of CE3MN-AC?
CE3MN-AC is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CE3MN-SA and CE3MN-AC?
SA is the default condition — the only condition in which the grade may be supplied to A890/A995 — pick it for all seawater, offshore and chemical castings. AC: reference condition only: intermetallic and nitride precipitation from casting leaves low toughness and degraded corrosion resistance, so parts must be solution treated before service. Yield strength is 560 MPa in SA versus 540 MPa in AC.
Sources
- ASTM A995/A995M — Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for Pressure-Containing Parts — ASTM (2020)
- ASTM A890/A890M — Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex — ASTM (2018)
- EN 10283 — Corrosion-resistant steel castings (GX2CrNiMoN25-7-4, 1.4469/1.4477 family) — CEN (2019)
- Steel Castings Handbook, Supplement 8 — High Alloy Data Sheets, Corrosion Series — SFSA (2004)
- ASM Handbook Vol.1 & Vol.15 (Properties of Stainless Steels; Casting) — ASM International (2008)
- Sandvik SAF 2507 / UNS S32750 datasheet (physical property reference) — Alleima (Sandvik) (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.