Stainless Steel CE8MN-AC (Spheroidize annealed)
Heat-treated state
ASTM CE8MN · UNS J93345
Only for trial castings or non-corrosive structural use — as-cast CE8MN contains intermetallics and nitrides that sharply cut toughness and corrosion resistance.
Values for the AC condition
Other CE8MN tempers and conditions
CE8MN is listed in 3 conditions; see the grade overview at CE8MN.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACThis page Spheroidize annealed | Only for trial castings or non-corrosive structural use — as-cast CE8MN contains intermetallics and nitrides that sharply cut toughness and corrosion resistance. | 480 | 690 | 12 | 22 HRC | 2.2 % IACS |
SADefault Solution annealed ≥1120 °C and water quenched | Standard supply condition for all CE8MN castings — the only condition permitted by ASTM A890/A995 for corrosion service. | 500 | 720 | 30 | 20 HRC | — |
hot isostatically pressed then solution annealed and quenched | Choose for pressure-retaining or fatigue-critical castings where internal porosity must be closed and radiographic quality raised. | 510 | 750 | 34 | 20 HRC | 2.2 % IACS |
What is CE8MN-AC?
CE8MN-AC is CE8MN heat treated to AC — only for trial castings or non-corrosive structural use — as-cast CE8MN contains intermetallics and nitrides that sharply cut toughness and corrosion resistance. CE8MN-AC has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 195 GPa (28.3 Msi). CE8MN-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). 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
- Limited ductility — 12%, worse than 95% of stainless steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 91% of stainless steel grades
- Limited formability — 18/100, worse than 89% of stainless steel grades
- Difficult to weld — 50/100, worse than 77% of stainless steel grades
CE8MN-AC properties
Typical room-temperature values for CE8MN-AC; 23 are specific to this condition. Other listed values are CE8MN reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
CE8MN-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).
Mechanical15
CE8MN-AC has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
CE8MN-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
CE8MN-AC conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of CE8MN-AC takes about 60 MJ of energy and emits 5 kg of CO₂ — more than 70% of stainless steel grades. Typical recycled content is 80%.
Manufacturability7
CE8MN-AC's machinability is poor (27/100, worse than 83% of stainless steel grades); weldability fair (50/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CE8MN-AC
Is CE8MN easy to machine?
Work-hardening and tough — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed and copious coolant; avoid dwelling to prevent glazing.
Can CE8MN be welded?
Weldable with GTAW/SMAW using over-alloyed 25Cr duplex filler (e.g. ER2594/E2209 class per application); control heat input and interpass ≤150 °C, no preheat, and re-solution-anneal major repairs to restore phase balance.
Can CE8MN be formed, bent or molded?
Supplied as sand or investment castings; provide generous risers and controlled solidification, and always solution anneal ≥1120 °C with rapid water quench to dissolve sigma and chi phases.
What surface finishes work on CE8MN?
Pickle and passivate after welding or grinding to remove heat tint and restore the passive film; takes a good mechanical polish, no anodizing applicable.
CE8MN 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 | ≤ 0.08 | 0.06 |
| Mn | ≤ 1 | 0.7 |
| Si | ≤ 1.5 | 1 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Cr | 22.5 – 25.5 | 24 |
| Ni | 8 – 11 | 9.5 |
| Mo | 3 – 4.5 | 3.7 |
| NNitrogen stabilises austenite and raises pitting resistance | 0.1 – 0.3 | 0.2 |
| Fe | balance | — |
CE8MN-AC — frequently asked
What is CE8MN-AC used for?
CE8MN-AC is typically used for chemical process pumps, valves for aggressive media and marine and offshore castings. In short: higher-nickel cast duplex; better corrosion than CD4MCu; 315 °C service ceiling.
What is the yield strength of CE8MN-AC?
CE8MN-AC has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 75% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is CE8MN-AC easy to machine?
Not especially — machinability is rated poor (27/100, worse than 83% of stainless steel grades). Work-hardening and tough — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed and copious coolant; avoid dwelling to prevent glazing.
Can CE8MN-AC be welded?
With care — weldability is rated fair (50/100). Weldable with GTAW/SMAW using over-alloyed 25Cr duplex filler (e.g. ER2594/E2209 class per application); control heat input and interpass ≤150 °C, no preheat, and re-solution-anneal major repairs to restore phase balance.
What surface finishes work on CE8MN-AC?
Pickle and passivate after welding or grinding to remove heat tint and restore the passive film; takes a good mechanical polish, no anodizing applicable.
Can CE8MN-AC be formed, bent or molded?
Supplied as sand or investment castings; provide generous risers and controlled solidification, and always solution anneal ≥1120 °C with rapid water quench to dissolve sigma and chi phases.
What is the maximum service temperature of CE8MN-AC?
CE8MN-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 CE8MN-SA and CE8MN-AC?
SA is the default condition — standard supply condition for all CE8MN castings — the only condition permitted by ASTM A890/A995 for corrosion service. AC: only for trial castings or non-corrosive structural use — as-cast CE8MN contains intermetallics and nitrides that sharply cut toughness and corrosion resistance. Yield strength is 500 MPa in SA versus 480 MPa in AC.
Sources
- ASTM A890/A890M — Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex — ASTM International (2023)
- ASTM A995/A995M — Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for Pressure-Containing Parts — ASTM International (2020)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- UNS J93345 alloy data — SAE/ASTM Unified Numbering System (2020)
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.