Stainless Steel 1.4584-AC (Spheroidize annealed)
Heat-treated state
EN 1.4584
Only for non-corrosion structural or rough-machining stock; carbide/σ networks strongly reduce ductility and acid resistance, so not accepted by EN 10213 for pressure service.
Values for the AC condition
Other 1.4584 tempers and conditions
1.4584 is listed in 4 conditions; see the grade overview at 1.4584.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
STDefault Solution annealed | Standard delivery condition for all pressure and corrosion-service castings; dissolves carbides and σ/χ phases for full corrosion resistance. | 230 | 490 | 40 | 160 HB | 1.7 % IACS |
Hot isostatically pressed then solution annealed | Choose for thick-section or high-pressure pump/valve castings where shrinkage porosity must be closed and fatigue/impact scatter minimised. | 240 | 510 | 45 | 160 HB | 1.7 % IACS |
ACThis page Spheroidize annealed | Only for non-corrosion structural or rough-machining stock; carbide/σ networks strongly reduce ductility and acid resistance, so not accepted by EN 10213 for pressure service. | 240 | 460 | 20 | 180 HB | 1.7 % IACS |
Centrifugally cast, solution annealed | Centrifugal tube/sleeve/ring product form with denser, finer structure; pick for acid-service pipe spools and pump liners. | 245 | 520 | 42 | 165 HB | 1.7 % IACS |
What is 1.4584-AC?
1.4584-AC is 1.4584 heat treated to AC — only for non-corrosion structural or rough-machining stock; carbide/σ networks strongly reduce ductility and acid resistance, so not accepted by EN 10213 for pressure service. 1.4584-AC has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 190 GPa (27.6 Msi). 1.4584-AC has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,320°C (2,408 °F). ST is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Low strength — 240 MPa (34.8 ksi), worse than 96% of stainless steel grades
- Poor heat conductor — 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
1.4584-AC properties
Typical room-temperature values for 1.4584-AC; 22 are specific to this condition. Other listed values are 1.4584 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4584-AC has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Mechanical16
1.4584-AC has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 190 GPa (27.6 Msi).
Thermal6
1.4584-AC is rated for continuous service to 300°C (572 °F). It conducts heat at 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades. Thermal expansion is 15.8 µm/m·K (8.78 µin/in·°F).
Electrical3
1.4584-AC conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4584-AC takes about 65 MJ of energy and emits 5.5 kg of CO₂ — more than 79% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
1.4584-AC's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability good (55/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4584-AC
Is 1.4584 easy to machine?
Tough and work-hardening — use rigid setups, sharp positive-rake carbide, heavy positive feed, low-to-moderate speed and copious flood coolant; never dwell or rub.
Can 1.4584 be welded?
Readily GTAW/SMAW welded with over-alloyed 385/904L or Ni-base (ERNiCrMo-3) filler; keep interpass below ~150 °C, low heat input, no preheat, and solution anneal + quench after major repair welds if full acid resistance is required.
Can 1.4584 be formed, bent or molded?
Sand and investment casting with generous risering and chills to counter the wide freezing range; limited cold straightening only, hot working 1150–1200 °C followed by rapid cooling.
What surface finishes work on 1.4584?
Pickle and passivate in HNO₃/HF after casting and welding to restore the passive film; grinds and polishes well, no anodising (n/a for stainless).
1.4584 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 |
|---|---|---|
| Cultra-low carbon, intergranular corrosion control | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.6 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 19 – 21 | 20 |
| Ni | 24 – 26 | 25 |
| Mo | 4 – 5 | 4.5 |
| Cusulfuric-acid resistance; ACI CN7M variant runs 3.0–4.0 % Cu with 27.5–30.5 % Ni | 1 – 2 | 1.5 |
| Fe | balance | — |
1.4584-AC — frequently asked
What is 1.4584-AC used for?
1.4584-AC is typically used for acid process pump casings, chemical valve bodies, sulfuric acid service impellers, phosphoric acid plant castings, pickling line pump components and agitator and mixer castings. In short: alloy 20 casting equivalent; sulfuric acid service; copper-bearing austenitic casting.
What is the yield strength of 1.4584-AC?
1.4584-AC has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 96% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4584-AC easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Tough and work-hardening — use rigid setups, sharp positive-rake carbide, heavy positive feed, low-to-moderate speed and copious flood coolant; never dwell or rub.
Can 1.4584-AC be welded?
Yes — weldability is rated good (55/100). Readily GTAW/SMAW welded with over-alloyed 385/904L or Ni-base (ERNiCrMo-3) filler; keep interpass below ~150 °C, low heat input, no preheat, and solution anneal + quench after major repair welds if full acid resistance is required.
What surface finishes work on 1.4584-AC?
Pickle and passivate in HNO₃/HF after casting and welding to restore the passive film; grinds and polishes well, no anodising (n/a for stainless).
Can 1.4584-AC be formed, bent or molded?
Sand and investment casting with generous risering and chills to counter the wide freezing range; limited cold straightening only, hot working 1150–1200 °C followed by rapid cooling.
What is the maximum service temperature of 1.4584-AC?
1.4584-AC is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4584-ST and 1.4584 CENT-ST?
ST is the default condition — standard delivery condition for all pressure and corrosion-service castings; dissolves carbides and σ/χ phases for full corrosion resistance. CENT-ST: centrifugal tube/sleeve/ring product form with denser, finer structure; pick for acid-service pipe spools and pump liners. Yield strength is 230 MPa in ST versus 245 MPa in CENT-ST.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A744/A744M — Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe Service (CN7M) — ASTM (2018)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (cast corrosion-resistant steels) — ASM International (1990)
- 904L / 1.4539 super-austenitic stainless steel datasheet — Outokumpu (2023)
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.