Stainless Steel 1.4517-AC (Spheroidize annealed)
Heat-treated state
EN 1.4517 · UNS J93370 · ASTM A890 Grade 1B
Only for non-corrosive, non-pressure or machining-stock parts — as-cast structure contains sigma/carbide risk and must not be used in service.
Values for the AC condition
Other 1.4517 tempers and conditions
1.4517 is listed in 4 conditions; see the grade overview at 1.4517.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACThis page Spheroidize annealed | Only for non-corrosive, non-pressure or machining-stock parts — as-cast structure contains sigma/carbide risk and must not be used in service. | 470 | 620 | 8 | 26 HRC | 2.1 % IACS |
STDefault Solution annealed | Standard delivery condition for all pressure- and corrosion-service castings; balanced ferrite/austenite, no sigma phase. | 520 | 700 | 25 | 23 HRC | — |
Hot isostatically pressed then solution treated and quenched | Choose for critical pump/valve castings needing closed microporosity, higher ductility and better fatigue/NDT acceptance. | 540 | 730 | 30 | 23 HRC | 2.2 % IACS |
Solution treated, quenched and copper-precipitation aged | Optional condition for maximum hardness/wear resistance on slurry-pump parts; sacrifices impact toughness and some corrosion margin, not permitted by ASTM A890 pressure ratings. | 700 | 850 | 10 | 34 HRC | 2.4 % IACS |
What is 1.4517-AC?
1.4517-AC is 1.4517 heat treated to AC — only for non-corrosive, non-pressure or machining-stock parts — as-cast structure contains sigma/carbide risk and must not be used in service. 1.4517-AC has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 195 GPa (28.3 Msi). 1.4517-AC has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). ST is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Limited service temperature — 200°C (392 °F), worse than 100% of stainless steel grades
- Limited ductility — 8%, worse than 99% of stainless steel grades
- Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 97% of stainless steel grades
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Difficult to machine — 24/100, worse than 93% of stainless steel grades
1.4517-AC properties
Typical room-temperature values for 1.4517-AC; 22 are specific to this condition. Other listed values are 1.4517 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4517-AC has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4517-AC has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4517-AC is rated for continuous service to 200°C (392 °F). It conducts heat at 14.5 W/m·K (8.38 BTU/hr·ft·°F), worse than 72% of stainless steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
1.4517-AC conducts electricity at 2.1 % IACS, worse than 73% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4517-AC takes about 55 MJ of energy and emits 4.6 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 70%.
Manufacturability7
1.4517-AC's machinability is poor (24/100, worse than 93% of stainless steel grades); weldability fair (40/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4517-AC
Is 1.4517 easy to machine?
Machine like 25Cr duplex: rigid setup, positive-rake carbide, low speed (~60–90 m/min) with heavy constant feed and flood coolant to beat work hardening and abrasive cast skin.
Can 1.4517 be welded?
Weldable with 25Cr duplex or 25-9-4 over-alloyed filler (GTAW/SMAW), low heat input, interpass <150 °C; full re-solution treatment and water quench after major repair welds is preferred to restore phase balance.
Can 1.4517 be formed, bent or molded?
Supplied as sand or investment castings only — design generous radii and directional solidification with risering; no cold forming.
What surface finishes work on 1.4517?
Pickle and passivate after heat treatment to remove scale; grinds and polishes reasonably well but the hard ferrite/austenite mix makes mirror finishing slow — no anodizing.
1.4517 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 to avoid carbide sensitisation | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.7 |
| Mn | ≤ 1.5 | 0.8 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 24.5 – 26.5 | 25.5 |
| Ni | 5 – 7 | 6 |
| Mo | 2.5 – 3.5 | 3 |
| Cuprecipitation-hardenable, improves H2SO4 resistance | 2.5 – 3.5 | 3 |
| N | 0.12 – 0.25 | 0.18 |
| Fe | balance | — |
1.4517-AC — frequently asked
What is 1.4517-AC used for?
1.4517-AC is typically used for pump casings and impellers, valve bodies, seawater and brine handling and oil & gas equipment. In short: standard A890 1B duplex; erosion-resistant pump castings; high strength, high chloride resistance.
What is the yield strength of 1.4517-AC?
1.4517-AC has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 74% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4517-AC easy to machine?
Not especially — machinability is rated poor (24/100, worse than 93% of stainless steel grades). Machine like 25Cr duplex: rigid setup, positive-rake carbide, low speed (~60–90 m/min) with heavy constant feed and flood coolant to beat work hardening and abrasive cast skin.
Can 1.4517-AC be welded?
With care — weldability is rated fair (40/100). Weldable with 25Cr duplex or 25-9-4 over-alloyed filler (GTAW/SMAW), low heat input, interpass <150 °C; full re-solution treatment and water quench after major repair welds is preferred to restore phase balance.
What surface finishes work on 1.4517-AC?
Pickle and passivate after heat treatment to remove scale; grinds and polishes reasonably well but the hard ferrite/austenite mix makes mirror finishing slow — no anodizing.
Can 1.4517-AC be formed, bent or molded?
Supplied as sand or investment castings only — design generous radii and directional solidification with risering; no cold forming.
What is the maximum service temperature of 1.4517-AC?
1.4517-AC is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4517-ST and 1.4517-AC?
ST is the default condition — standard delivery condition for all pressure- and corrosion-service castings; balanced ferrite/austenite, no sigma phase. AC: only for non-corrosive, non-pressure or machining-stock parts — as-cast structure contains sigma/carbide risk and must not be used in service. Yield strength is 520 MPa in ST versus 470 MPa in AC.
Sources
- EN 10283 — Corrosion resistant steel castings (GX2CrNiMoCuN25-6-3-3, 1.4517) — CEN (2010)
- ASTM A890/A890M — Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Grade 1B, CD4MCuN) — ASTM International (2018)
- ASTM A995/A995M — Castings, Austenitic-Ferritic (Duplex) Stainless Steel, for Pressure-Containing Parts — ASTM International (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast stainless steels) — ASM International (1990)
- Duplex stainless steel casting grade datasheets (25Cr Cu-bearing) — Various foundries (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.