Stainless Steel 1.4859-AC (Spheroidize annealed)
Heat-treated state
EN 1.4859
Chosen for purely high-temperature furnace/glass-plant parts where the service temperature itself re-solutions the structure and cost matters more than as-delivered ductility.
Values for the AC condition
Other 1.4859 tempers and conditions
1.4859 is listed in 3 conditions; see the grade overview at 1.4859.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
STDefault Solution annealed | Standard supply condition for pressure-containing and welded castings; dissolves carbide networks and gives best ductility, toughness and intergranular-corrosion resistance. | 235 | 480 | 28 | 150 HB | — |
ACThis page Spheroidize annealed | Chosen for purely high-temperature furnace/glass-plant parts where the service temperature itself re-solutions the structure and cost matters more than as-delivered ductility. | 245 | 470 | 20 | 160 HB | 1.7 % IACS |
As-welded deposit | Condition of weld-repaired or fabricated assemblies where re-solution annealing is impractical; Nb stabilization keeps the HAZ resistant to sensitization. | 250 | 460 | 18 | 165 HB | 1.7 % IACS |
What is 1.4859-AC?
1.4859-AC is 1.4859 heat treated to AC — chosen for purely high-temperature furnace/glass-plant parts where the service temperature itself re-solutions the structure and cost matters more than as-delivered ductility. 1.4859-AC has a yield strength of 245 MPa (35.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 94% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 172 GPa (24.9 Msi). 1.4859-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,330°C (2,426 °F). ST is the default condition FabDigit quotes; AC is available on request or by drawing note.
Advantages
- High service temperature — 1,050°C (1,922 °F), better than 91% of stainless steel grades
Limitations
- Low stiffness — 172 GPa (24.9 Msi), worse than 99% of stainless steel grades
- Low strength — 245 MPa (35.5 ksi), worse than 94% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- Limited formability — 12/100, worse than 93% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
1.4859-AC properties
Typical room-temperature values for 1.4859-AC; 22 are specific to this condition. Other listed values are 1.4859 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4859-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,330°C (2,426 °F).
Mechanical14
1.4859-AC has a yield strength of 245 MPa (35.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 94% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 172 GPa (24.9 Msi).
Thermal6
1.4859-AC is rated for continuous service to 1,050°C (1,922 °F). It conducts heat at 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 85% of stainless steel grades. Thermal expansion is 15 µm/m·K (8.33 µin/in·°F).
Electrical3
1.4859-AC conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4859-AC takes about 78 MJ of energy and emits 5.8 kg of CO₂ — more than 87% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
1.4859-AC's machinability is poor (26/100, worse than 84% of stainless steel grades); weldability very good (72/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4859-AC
Is 1.4859 easy to machine?
Machine like a high-Ni austenitic: rigid setup, sharp positive-rake carbide, low speed (~30–60 m/min) and heavy positive feed to cut under the work-hardened skin, with flood coolant.
Can 1.4859 be welded?
Very good for a heat-resistant cast grade — GTAW/SMAW with matching 32-20Nb or Ni-base (ERNiCr-3) filler, no preheat needed, keep interpass below ~150 °C and avoid post-weld holding in the 650–900 °C range.
Can 1.4859 be formed, bent or molded?
Supplied only as sand, investment or centrifugal castings; provide generous risering for the wide freezing range and design uniform sections to limit hot tearing.
What surface finishes work on 1.4859?
Blast plus pickle/passivate to remove casting scale; ground and polished surfaces improve oxidation life, and no plating or anodizing is used in service.
1.4859 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 for weldability | 0.05 – 0.15 | 0.1 |
| Siraises oxidation/carburization resistance | 1 – 2 | 1.5 |
| Mn | ≤ 1.5 | 1 |
| Pimpurity limit | ≤ 0.04 | — |
| Simpurity limit | ≤ 0.03 | — |
| Cr | 19 – 21 | 20 |
| Ni | 31 – 33 | 32 |
| Nbstabilizer against intergranular corrosion; A351 CT15C uses 0.5–1.5 | 0.8 – 1.8 | 1.2 |
| Fe | balance | — |
1.4859-AC — frequently asked
What is 1.4859-AC used for?
1.4859-AC is typically used for glass manufacturing rollers and molds, chemical process vessel internals and high-temperature valve and pump bodies. In short: most weldable of family; highest ductility cast grade; low-carbon Nb-stabilized.
What is the yield strength of 1.4859-AC?
1.4859-AC has a typical yield strength of 245 MPa (35.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 94% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.4859-AC easy to machine?
Not especially — machinability is rated poor (26/100, worse than 84% of stainless steel grades). Machine like a high-Ni austenitic: rigid setup, sharp positive-rake carbide, low speed (~30–60 m/min) and heavy positive feed to cut under the work-hardened skin, with flood coolant.
Can 1.4859-AC be welded?
Yes — weldability is rated very good (72/100). Very good for a heat-resistant cast grade — GTAW/SMAW with matching 32-20Nb or Ni-base (ERNiCr-3) filler, no preheat needed, keep interpass below ~150 °C and avoid post-weld holding in the 650–900 °C range.
What surface finishes work on 1.4859-AC?
Blast plus pickle/passivate to remove casting scale; ground and polished surfaces improve oxidation life, and no plating or anodizing is used in service.
Can 1.4859-AC be formed, bent or molded?
Supplied only as sand, investment or centrifugal castings; provide generous risering for the wide freezing range and design uniform sections to limit hot tearing.
What is the maximum service temperature of 1.4859-AC?
1.4859-AC is rated for continuous use to about 1,050°C (1,922 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4859-ST and 1.4859-AW?
ST is the default condition — standard supply condition for pressure-containing and welded castings; dissolves carbide networks and gives best ductility, toughness and intergranular-corrosion resistance. AW: condition of weld-repaired or fabricated assemblies where re-solution annealing is impractical; Nb stabilization keeps the HAZ resistant to sensitization. Yield strength is 235 MPa in ST versus 250 MPa in AW.
Sources
- EN 10295 — Heat resistant steel castings — CEN (2002)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (grade CT15C) — ASTM International (2018)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (heat-resistant castings) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Heat-resistant cast alloy 32Ni-20Cr-Nb data sheets — foundry producers (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.