Stainless Steel 1.4416-AC (Spheroidize annealed)
Heat-treated state
EN 1.4416
Only for non-corrosive structural or rough/oversize blanks — interdendritic σ/χ and carbide/nitride segregation cut ductility, toughness and corrosion resistance.
Values for the AC condition
Other 1.4416 tempers and conditions
1.4416 is listed in 4 conditions; see the grade overview at 1.4416.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed 1080–1150 °C + rapid water quench | Standard delivery condition for all corrosion-service castings — maximum corrosion resistance and ductility, fully austenitic and intermetallic-free. | 270 | 520 | 35 | 170 HB | — |
Hot isostatically pressed then solution annealed and quenched | Chosen for pressure-retaining or radiographically critical pump/valve parts: HIP closes microporosity, raising ductility, toughness and fatigue life. | 280 | 545 | 42 | 175 HB | 1.7 % IACS |
As-welded deposit | Condition of production weld repairs on thin sections where re-solution treatment is impractical; expect somewhat lower HAZ ductility and locally reduced pitting resistance. | 280 | 510 | 28 | 9 HRC | 1.6 % IACS |
ACThis page Spheroidize annealed | Only for non-corrosive structural or rough/oversize blanks — interdendritic σ/χ and carbide/nitride segregation cut ductility, toughness and corrosion resistance. | 290 | 500 | 20 | 11 HRC | 1.6 % IACS |
What is 1.4416-AC?
1.4416-AC is 1.4416 heat treated to AC — only for non-corrosive structural or rough/oversize blanks — interdendritic σ/χ and carbide/nitride segregation cut ductility, toughness and corrosion resistance. 1.4416-AC has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 72% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 195 GPa (28.3 Msi). 1.4416-AC has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,330°C (2,426 °F). SA is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Low electrical conductivity — 1.6 % IACS, worse than 99% of stainless steel grades
- Poor heat conductor — 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
1.4416-AC properties
Typical room-temperature values for 1.4416-AC; 23 are specific to this condition. Other listed values are 1.4416 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4416-AC has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,330°C (2,426 °F).
Mechanical15
1.4416-AC has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 72% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4416-AC is rated for continuous service to 400°C (752 °F). It conducts heat at 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
1.4416-AC conducts electricity at 1.6 % IACS, worse than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4416-AC takes about 75 MJ of energy and emits 5.5 kg of CO₂ — more than 84% of stainless steel grades. Typical recycled content is 55%.
Manufacturability8
1.4416-AC's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability good (55/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4416-AC
Is 1.4416 easy to machine?
Tough and strongly work-hardening: use rigid setups, positive-rake coated carbide, low speed with heavy feed, generous flood coolant and no dwelling to avoid glazing.
Can 1.4416 be welded?
GTAW/GMAW or SMAW with over-alloyed Ni-base filler (e.g. ERNiCrMo-3/-4); keep heat input and interpass temperature low, no preheat, and back-purge to avoid σ-phase and hot cracking.
Can 1.4416 be formed, bent or molded?
Supplied as sand or investment castings with a wide freezing range — needs good gating/feeding, chills on heavy sections and solution treatment plus water quench after cleaning.
What surface finishes work on 1.4416?
Pickle and passivate (HNO₃ or HNO₃/HF) or electropolish after grinding; mechanical polishing works but casting microporosity limits mirror finishes; no anodizing.
1.4416 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 |
|---|---|---|
| Cextra-low carbon to avoid carbide precipitation | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.6 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | — |
| S | ≤ 0.02 | — |
| Cr | 19 – 21 | 20 |
| Ni | 24 – 26 | 25 |
| Mo | 4 – 5 | 4.5 |
| Nstrengthens and stabilises austenite, raises PREN | 0.1 – 0.2 | 0.15 |
| Cuoften added for sulfuric acid service | ≤ 1.5 | 0.8 |
| Fe | balance | — |
1.4416-AC — frequently asked
What is 1.4416-AC used for?
1.4416-AC is typically used for sulfuric acid pumps, flue-gas desulfurization components and chemical process castings. In short: superaustenitic acid-service casting; highest corrosion resistance here; lowest machinability in family.
What is the yield strength of 1.4416-AC?
1.4416-AC has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 72% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4416-AC easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of stainless steel grades). Tough and strongly work-hardening: use rigid setups, positive-rake coated carbide, low speed with heavy feed, generous flood coolant and no dwelling to avoid glazing.
Can 1.4416-AC be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW or SMAW with over-alloyed Ni-base filler (e.g. ERNiCrMo-3/-4); keep heat input and interpass temperature low, no preheat, and back-purge to avoid σ-phase and hot cracking.
What surface finishes work on 1.4416-AC?
Pickle and passivate (HNO₃ or HNO₃/HF) or electropolish after grinding; mechanical polishing works but casting microporosity limits mirror finishes; no anodizing.
Can 1.4416-AC be formed, bent or molded?
Supplied as sand or investment castings with a wide freezing range — needs good gating/feeding, chills on heavy sections and solution treatment plus water quench after cleaning.
What is the maximum service temperature of 1.4416-AC?
1.4416-AC is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4416-SA and 1.4416-AC?
SA is the default condition — standard delivery condition for all corrosion-service castings — maximum corrosion resistance and ductility, fully austenitic and intermetallic-free. AC: only for non-corrosive structural or rough/oversize blanks — interdendritic σ/χ and carbide/nitride segregation cut ductility, toughness and corrosion resistance. Yield strength is 270 MPa in SA versus 290 MPa in AC.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- Superaustenitic cast stainless steel (6Mo-class) datasheets — Foundry/producer literature (2022)
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.