Stainless Steel 1.4581-AC (Spheroidize annealed)
Heat-treated state
EN 1.4581
Only for non-pressure, non-corrosive decorative or structural parts; carbides/interdendritic phases remain, corrosion and toughness are reduced.
Values for the AC condition
Other 1.4581 tempers and conditions
1.4581 is listed in 3 conditions; see the grade overview at 1.4581.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed 1050–1150 °C, water quenched | Standard supply condition for pump casings, valve bodies and fittings per EN 10213. | 250 | 520 | 35 | 160 HB | 2.3 % IACS |
ACThis page Spheroidize annealed | Only for non-pressure, non-corrosive decorative or structural parts; carbides/interdendritic phases remain, corrosion and toughness are reduced. | 250 | 490 | 25 | 175 HB | 2.3 % IACS |
Centrifugally cast, solution annealed | Choose for tubes/rings and sleeves where the denser, finer centrifugal structure raises strength and soundness. | 270 | 560 | 38 | 170 HB | 2.3 % IACS |
What is 1.4581-AC?
1.4581-AC is 1.4581 heat treated to AC — only for non-pressure, non-corrosive decorative or structural parts; carbides/interdendritic phases remain, corrosion and toughness are reduced. 1.4581-AC has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 195 GPa (28.3 Msi). 1.4581-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% 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.
Limitations
- Low strength — 250 MPa (36.3 ksi), worse than 91% of stainless steel grades
- Limited formability — 15/100, worse than 91% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
1.4581-AC properties
Typical room-temperature values for 1.4581-AC; 21 are specific to this condition. Other listed values are 1.4581 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4581-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4581-AC has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4581-AC is rated for continuous service to 600°C (1,112 °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 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4581-AC conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4581-AC takes about 55 MJ of energy and emits 4.8 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
1.4581-AC's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (70/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4581-AC
Is 1.4581 easy to machine?
Work-hardens and tears: use rigid setups, sharp coated carbide, positive rake, low speed / heavy feed and copious coolant; avoid dwelling.
Can 1.4581 be welded?
Excellent — Nb stabilization allows welding without post-weld solution anneal; use ER347/ER318 (Nb-bearing) or 316L filler with low heat input.
Can 1.4581 be formed, bent or molded?
Supplied as sand, investment or centrifugal castings; keep sections uniform, feed heavily (long freezing range) and solution anneal + water quench after casting or major weld repair.
What surface finishes work on 1.4581?
Passivate per ASTM A967 or electropolish; shot blast/pickle to remove casting scale — not anodizable, plating rarely needed.
1.4581 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, Nb-stabilized | ≤ 0.07 | 0.05 |
| Si | ≤ 1.5 | 1 |
| Mn | ≤ 1.5 | 1 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.03 | 0.02 |
| Cr | 18 – 20 | 19 |
| Ni | 9 – 12 | 10.5 |
| Mo | 2 – 2.5 | 2.2 |
| Nb≥ 8×C, stabilizing addition | 0.4 – 1 | 0.7 |
| Fe | balance | — |
1.4581-AC — frequently asked
What is 1.4581-AC used for?
1.4581-AC is typically used for high-temperature valve bodies, chemical process pump casings, cast flanges and fittings, hot process gas manifolds, pressure-containing housings for steam service and pump impellers and wear rings. In short: stabilized CF8M casting; weld without re-annealing; 700 °C service with Mo.
What is the yield strength of 1.4581-AC?
1.4581-AC has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.4581-AC easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Work-hardens and tears: use rigid setups, sharp coated carbide, positive rake, low speed / heavy feed and copious coolant; avoid dwelling.
Can 1.4581-AC be welded?
Yes — weldability is rated very good (70/100). Excellent — Nb stabilization allows welding without post-weld solution anneal; use ER347/ER318 (Nb-bearing) or 316L filler with low heat input.
What surface finishes work on 1.4581-AC?
Passivate per ASTM A967 or electropolish; shot blast/pickle to remove casting scale — not anodizable, plating rarely needed.
Can 1.4581-AC be formed, bent or molded?
Supplied as sand, investment or centrifugal castings; keep sections uniform, feed heavily (long freezing range) and solution anneal + water quench after casting or major weld repair.
What is the maximum service temperature of 1.4581-AC?
1.4581-AC is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4581-SA and 1.4581 SA-CENT?
SA is the default condition — standard supply condition for pump casings, valve bodies and fittings per EN 10213. SA-CENT: choose for tubes/rings and sleeves where the denser, finer centrifugal structure raises strength and soundness. Yield strength is 250 MPa in SA versus 270 MPa in SA-CENT.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A351/A351M — Castings, austenitic, for pressure-containing parts — ASTM (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- EN 10088-1 physical property tables for austenitic stainless steels — CEN (2014)
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.