Stainless Steel CD3MN-AC (Spheroidize annealed)
Heat-treated state
ASTM CD3MN · UNS J92205 · EN 1.4470, GX2CrNiMoN22-5-3
Only for non-pressure, non-corrosive parts or intermediate stock — as-cast duplex has intermetallics and unbalanced phases, so corrosion and toughness are degraded.
Values for the AC condition
Other CD3MN tempers and conditions
CD3MN is listed in 5 conditions; see the grade overview at CD3MN.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACThis page Spheroidize annealed | Only for non-pressure, non-corrosive parts or intermediate stock — as-cast duplex has intermetallics and unbalanced phases, so corrosion and toughness are degraded. | 480 | 640 | 15 | 20 HRC | 2.2 % IACS |
SADefault Solution annealed ~1120 °C and water quenched | Standard supply condition for all pressure-retaining castings; restores the 50/50 ferrite–austenite balance and dissolves intermetallics. | 500 | 700 | 32 | 16 HRC | — |
Solution annealed with low-temperature impact qualification | Same heat treatment as SA but with tightened ferrite window and −46 °C Charpy testing for NORSOK/oil-and-gas subsea service. | 510 | 700 | 32 | 16 HRC | 2.2 % IACS |
hot isostatically pressed then solution annealed and quenched | Choose for critical subsea/high-pressure castings where internal porosity must be closed and impact/fatigue scatter minimized. | 520 | 730 | 36 | 17 HRC | 2.2 % IACS |
Centrifugally cast tube/ring, solution annealed and quenched | Pick for seamless duplex rings, sleeves and pipe where centrifugal casting gives a denser, finer structure than static casting. | 520 | 720 | 30 | 17 HRC | 2.2 % IACS |
What is CD3MN-AC?
CD3MN-AC is CD3MN heat treated to AC — only for non-pressure, non-corrosive parts or intermediate stock — as-cast duplex has intermetallics and unbalanced phases, so corrosion and toughness are degraded. CD3MN-AC has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 195 GPa (28.3 Msi). CD3MN-AC has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,385°C (2,525 °F). SA is the default condition FabDigit quotes; AC is available on request or by drawing note.
Advantages
- High strength — 480 MPa (69.6 ksi), better than 75% of stainless steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 99% of stainless steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 91% of stainless steel grades
- Limited formability — 15/100, worse than 91% of stainless steel grades
- Limited ductility — 15%, worse than 89% of stainless steel grades
- Difficult to weld — 50/100, worse than 77% of stainless steel grades
CD3MN-AC properties
Typical room-temperature values for CD3MN-AC; 23 are specific to this condition. Other listed values are CD3MN reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
CD3MN-AC has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,385°C (2,525 °F).
Mechanical17
CD3MN-AC has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
CD3MN-AC is rated for continuous service to 250°C (482 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
CD3MN-AC conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of CD3MN-AC takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 80%.
Manufacturability8
CD3MN-AC's machinability is poor (26/100, worse than 84% of stainless steel grades); weldability fair (50/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CD3MN-AC
Is CD3MN easy to machine?
Machine like a work-hardening duplex: rigid setup, sharp coated carbide, ~60–90 m/min cutting speed, heavy positive feed to stay under the hardened skin, and generous coolant; expect ~25 % of 1212 productivity.
Can CD3MN be welded?
Readily welded by GTAW/GMAW/SMAW with 2209 (25.10.4L) over-alloyed filler; control heat input ~0.5–2.5 kJ/mm and interpass <150 °C to keep 35–65 % ferrite, no preheat, no PWHT unless a full re-solution + quench is applied.
Can CD3MN be formed, bent or molded?
Sand or investment cast with generous risering (solidification range and shrinkage similar to CF8M), then mandatory solution treatment at ~1080–1150 °C with rapid water quench; heavy sections need quench modelling to avoid sigma phase.
What surface finishes work on CD3MN?
Grind/blast with iron-free media, then pickle in HNO₃–HF or passivate per ASTM A967; electropolishing gives the best pitting performance and no anodizing or plating is used.
CD3MN 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 to avoid sensitization | ≤ 0.03 | 0.02 |
| MnA995 4A allows 1.50 max; A890 4A 1.00 max | ≤ 1.5 | 0.8 |
| Si | ≤ 1 | 0.7 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Cr | 21 – 23.5 | 22.2 |
| Ni | 4.5 – 6.5 | 5.5 |
| Mo | 2.5 – 3.5 | 3 |
| Curesidual limit | ≤ 1 | 0.2 |
| Nstabilizes austenite, raises PREN | 0.1 – 0.3 | 0.17 |
| Fe | balance | — |
CD3MN-AC — frequently asked
What is CD3MN-AC used for?
CD3MN-AC is typically used for pump casings, valve bodies, impellers and marine and offshore castings. In short: cast 2205 equivalent; weldable duplex casting; stronger than cast CF8M.
What is the yield strength of CD3MN-AC?
CD3MN-AC has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 75% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is CD3MN-AC easy to machine?
Not especially — machinability is rated poor (26/100, worse than 84% of stainless steel grades). Machine like a work-hardening duplex: rigid setup, sharp coated carbide, ~60–90 m/min cutting speed, heavy positive feed to stay under the hardened skin, and generous coolant; expect ~25 % of 1212 productivity.
Can CD3MN-AC be welded?
With care — weldability is rated fair (50/100). Readily welded by GTAW/GMAW/SMAW with 2209 (25.10.4L) over-alloyed filler; control heat input ~0.5–2.5 kJ/mm and interpass <150 °C to keep 35–65 % ferrite, no preheat, no PWHT unless a full re-solution + quench is applied.
What surface finishes work on CD3MN-AC?
Grind/blast with iron-free media, then pickle in HNO₃–HF or passivate per ASTM A967; electropolishing gives the best pitting performance and no anodizing or plating is used.
Can CD3MN-AC be formed, bent or molded?
Sand or investment cast with generous risering (solidification range and shrinkage similar to CF8M), then mandatory solution treatment at ~1080–1150 °C with rapid water quench; heavy sections need quench modelling to avoid sigma phase.
What is the maximum service temperature of CD3MN-AC?
CD3MN-AC is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CD3MN-SA and CD3MN SA-HIP?
SA is the default condition — standard supply condition for all pressure-retaining castings; restores the 50/50 ferrite–austenite balance and dissolves intermetallics. SA-HIP: choose for critical subsea/high-pressure castings where internal porosity must be closed and impact/fatigue scatter minimized. Yield strength is 500 MPa in SA versus 520 MPa in SA-HIP.
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)
- Practical Guidelines for the Fabrication of Duplex Stainless Steels — IMOA (2014)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook, Supplement 8 — High Alloy Data Sheets, Corrosion Series — SFSA (2004)
- EN 10283 / GX2CrNiMoN22-5-3 (1.4470) cast corrosion-resistant steels — CEN (2010)
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.