Nickel Alloy CW6M-AC (Spheroidize annealed)
Heat-treated state
UNS J30107, N10276 · ASTM A494 CW6M
Only for non-corrosive structural or machining-stock use — interdendritic carbides/μ phase cut ductility and corrosion resistance; not an ASTM A494 delivery condition.
Values for the AC condition
Other CW6M tempers and conditions
CW6M is listed in 4 conditions; see the grade overview at CW6M.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed (≈1150–1180 °C, water quenched) per ASTM A494 | Standard supply condition for all corrosion-service castings; maximum ductility and corrosion resistance. | 310 | 550 | 40 | 185 HB | 1.4 % IACS |
weld repaired then re-solution annealed | Post-repair condition for foundry-corrected castings; restores homogeneous corrosion performance in the weld zone. | 310 | 540 | 35 | 185 HB | 1.4 % IACS |
hot isostatically pressed then solution annealed | Choose for pressure-containing or fatigue-loaded castings where microporosity must be closed (radiographic Level 1 parts). | 325 | 585 | 48 | 185 HB | 1.4 % IACS |
ACThis page Spheroidize annealed | Only for non-corrosive structural or machining-stock use — interdendritic carbides/μ phase cut ductility and corrosion resistance; not an ASTM A494 delivery condition. | 330 | 500 | 12 | 205 HB | 1.3 % IACS |
What is CW6M-AC?
CW6M-AC is CW6M heat treated to AC — only for non-corrosive structural or machining-stock use — interdendritic carbides/μ phase cut ductility and corrosion resistance; not an ASTM A494 delivery condition. CW6M-AC has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 67% of nickel alloy grades. Elongation at break is 12% and the elastic modulus is 198 GPa (28.7 Msi). CW6M-AC has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 91% of nickel alloy grades. It melts at 1,325°C (2,417 °F). SA is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Poor heat conductor — 9.8 W/m·K (5.66 BTU/hr·ft·°F), worse than 92% of nickel alloy grades
- Low fracture toughness — 70 MPa·√m (63.7 ksi·√in), worse than 85% of nickel alloy grades
- Limited ductility — 12%, worse than 83% of nickel alloy grades
CW6M-AC properties
Typical room-temperature values for CW6M-AC; 22 are specific to this condition. Other listed values are CW6M reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
CW6M-AC has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 91% of nickel alloy grades. It melts at 1,325°C (2,417 °F).
Mechanical15
CW6M-AC has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 67% of nickel alloy grades. Elongation at break is 12% and the elastic modulus is 198 GPa (28.7 Msi).
Thermal6
CW6M-AC is rated for continuous service to 550°C (1,022 °F). It conducts heat at 9.8 W/m·K (5.66 BTU/hr·ft·°F), worse than 92% of nickel alloy grades. Thermal expansion is 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
CW6M-AC conducts electricity at 1.3 % IACS, worse than 89% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 51% of nickel alloy grades.
Sustainability4
Producing a kilogram of CW6M-AC takes about 155 MJ of energy and emits 13.5 kg of CO₂ — less than 58% of nickel alloy grades. Typical recycled content is 45%.
Manufacturability7
CW6M-AC's machinability is poor (17/100, worse than 69% of nickel alloy grades); weldability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CW6M-AC
Is CW6M easy to machine?
Rigid setups, positive-rake carbide or ceramic-free coated inserts, low speed (15–25 m/min carbide) with heavy feed and flood coolant to cut under the work-hardened layer; never dwell.
Can CW6M be welded?
GTAW/GMAW with ERNiCrMo-4 (C-276) filler, low heat input, interpass <120 °C, no preheat; re-solution anneal after major repairs to restore corrosion resistance.
Can CW6M be formed, bent or molded?
Supplied as sand or investment castings — wide freezing range needs generous risering, chills and argon/vacuum melting to avoid microshrinkage and hot tears; not a wrought/cold-formed product.
What surface finishes work on CW6M?
Grit-blast plus pickling in HNO₃-HF to remove the Cr-depleted casting skin, then passivate or electropolish; no anodizing, plating rarely needed.
CW6M 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 C-type grade | ≤ 0.07 | 0.03 |
| Mn | ≤ 1 | 0.6 |
| Si | ≤ 1 | 0.6 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 17 – 20 | 18.5 |
| Mo | 17 – 20 | 18.5 |
| Fe | ≤ 3 | 2 |
| W | ≤ 1 | 0.4 |
| Niremainder, ≈57–62 % | balance | — |
CW6M-AC — frequently asked
What is CW6M-AC used for?
CW6M-AC is typically used for pump bodies for FGD systems, chemical processing valves and pulp and paper bleaching equipment. In short: cast C-276 standard; top pitting and crevice resistance; FGD industry default.
What is the yield strength of CW6M-AC?
CW6M-AC has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 67% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is CW6M-AC easy to machine?
Not especially — machinability is rated poor (17/100, worse than 69% of nickel alloy grades). Rigid setups, positive-rake carbide or ceramic-free coated inserts, low speed (15–25 m/min carbide) with heavy feed and flood coolant to cut under the work-hardened layer; never dwell.
Can CW6M-AC be welded?
Yes — weldability is rated good (60/100). GTAW/GMAW with ERNiCrMo-4 (C-276) filler, low heat input, interpass <120 °C, no preheat; re-solution anneal after major repairs to restore corrosion resistance.
What surface finishes work on CW6M-AC?
Grit-blast plus pickling in HNO₃-HF to remove the Cr-depleted casting skin, then passivate or electropolish; no anodizing, plating rarely needed.
Can CW6M-AC be formed, bent or molded?
Supplied as sand or investment castings — wide freezing range needs generous risering, chills and argon/vacuum melting to avoid microshrinkage and hot tears; not a wrought/cold-formed product.
What is the maximum service temperature of CW6M-AC?
CW6M-AC is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CW6M-SA and CW6M-AC?
SA is the default condition — standard supply condition for all corrosion-service castings; maximum ductility and corrosion resistance. AC: only for non-corrosive structural or machining-stock use — interdendritic carbides/μ phase cut ductility and corrosion resistance; not an ASTM A494 delivery condition. Yield strength is 310 MPa in SA versus 330 MPa in AC.
Sources
- ASTM A494/A494M — Castings, Nickel and Nickel Alloy — ASTM International (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (cast corrosion-resistant Ni alloys) — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- HASTELLOY C-276 alloy principal features and physical properties — Haynes International (2020)
- UNS N30107 alloy data — SAE/ASTM Metals & Alloys in the Unified Numbering System (2017)
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.