Stainless Steel 1.4659-SA (Solution annealed)
Heat-treated state · default condition
EN 1.4659 · UNS S31266 · also Uranus SB8
Standard supply condition for plate, sheet, bar and tube; maximum corrosion resistance and toughness.
Values for the SA condition
Other 1.4659 tempers and conditions
1.4659 is listed in 3 conditions; see the grade overview at 1.4659.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
forged then solution annealed (flanges, valve bodies, fittings) | Heavy forged sections per ASTM A182-type practice for valves, flanges and pump parts. | 450 | 800 | 45 | 205 HB | 1.7 % IACS |
SADefaultThis page Solution annealed | Standard supply condition for plate, sheet, bar and tube; maximum corrosion resistance and toughness. | 460 | 820 | 48 | 210 HB | — |
Cold drawn | Bar stock for shafts, fasteners and valve trim where tighter tolerance and higher yield strength are needed. | 650 | 930 | 30 | 25 HRC | 1.7 % IACS |
What is 1.4659-SA?
1.4659-SA is 1.4659 heat treated to SA — standard supply condition for plate, sheet, bar and tube; maximum corrosion resistance and toughness. 1.4659-SA has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 73% of stainless steel grades. Elongation at break is 48% and the elastic modulus is 195 GPa (28.3 Msi). 1.4659-SA has a density of 8.05 g/cm³ (0.291 lb/in³), heavier than 98% of stainless steel grades. It melts at 1,330°C (2,426 °F).
Advantages
- Good corrosion resistance — 93/100, better than 100% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- Ductile — tolerates forming and impact — 48%, better than 85% of stainless steel grades
Limitations
- Poor heat conductor — 11 W/m·K (6.36 BTU/hr·ft·°F), worse than 99% of stainless steel grades
- Difficult to machine — 18/100, worse than 99% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- High embodied carbon — 6.2 kg CO₂/kg, worse than 90% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
1.4659-SA properties
Typical room-temperature values for 1.4659-SA; 11 are specific to this condition. Other listed values are 1.4659 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4659-SA has a density of 8.05 g/cm³ (0.291 lb/in³), heavier than 98% of stainless steel grades. It melts at 1,330°C (2,426 °F).
Mechanical14
1.4659-SA has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 73% of stainless steel grades. Elongation at break is 48% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4659-SA is rated for continuous service to 400°C (752 °F). It conducts heat at 11 W/m·K (6.36 BTU/hr·ft·°F), worse than 99% of stainless steel grades. Thermal expansion is 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
1.4659-SA conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (93/100), better than 100% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4659-SA takes about 85 MJ of energy and emits 6.2 kg of CO₂ — more than 92% of stainless steel grades. Typical recycled content is 40%.
Manufacturability6
1.4659-SA's machinability is poor (18/100, worse than 99% of stainless steel grades); weldability good (65/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4659-SA
Is 1.4659 easy to machine?
Treat as a Ni-base alloy: rigid setups, positive-rake coated carbide, heavy positive feed to cut under the work-hardened layer, low speeds (~20–40 m/min) and copious high-pressure coolant.
Can 1.4659 be welded?
GTAW/GMAW/SMAW with overalloyed Ni-base filler (ERNiCrMo-3/-13 or ERNiCrMo-14), low heat input, interpass < 100 °C, no preheat and no PWHT; back-purge with Ar or Ar+N₂ to preserve corrosion resistance.
Can 1.4659 be formed, bent or molded?
Cold forms readily but with ~2× the force of 304 and strong springback; hot work 1100–1200 °C followed by mandatory solution anneal and water quench.
What surface finishes work on 1.4659?
Pickle (HNO₃-HF) or bead-blast plus passivation after welding to remove heat tint; electropolishing gives the best surface for high-purity or seawater duty; anodizing is not applicable.
1.4659 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 intergranular resistance | ≤ 0.03 | 0.02 |
| Si | ≤ 0.8 | 0.3 |
| Mnraises N solubility | 2 – 4 | 3 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.02 | 0 |
| Cr | 23 – 25 | 24 |
| Ni | 21 – 24 | 22 |
| Mo | 5 – 7 | 6 |
| Cuimproves reducing-acid resistance | 1 – 2.5 | 1.5 |
| Wboosts pitting/crevice resistance | 1.5 – 2.5 | 2 |
| Naustenite stabiliser, strength and PREN | 0.35 – 0.6 | 0.45 |
| Fe | balance | — |
1.4659-SA — frequently asked
What is 1.4659-SA used for?
1.4659-SA is typically used for FGD scrubber components, seawater and brine handling, chemical process vessels and marine and offshore piping. In short: tungsten-alloyed superaustenitic; beyond 6Mo corrosion resistance; nickel-alloy behaviour, stainless base.
What is the yield strength of 1.4659-SA?
1.4659-SA has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 73% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.4659-SA easy to machine?
Not especially — machinability is rated poor (18/100, worse than 99% of stainless steel grades). Treat as a Ni-base alloy: rigid setups, positive-rake coated carbide, heavy positive feed to cut under the work-hardened layer, low speeds (~20–40 m/min) and copious high-pressure coolant.
Can 1.4659-SA be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW/SMAW with overalloyed Ni-base filler (ERNiCrMo-3/-13 or ERNiCrMo-14), low heat input, interpass < 100 °C, no preheat and no PWHT; back-purge with Ar or Ar+N₂ to preserve corrosion resistance.
What surface finishes work on 1.4659-SA?
Pickle (HNO₃-HF) or bead-blast plus passivation after welding to remove heat tint; electropolishing gives the best surface for high-purity or seawater duty; anodizing is not applicable.
Can 1.4659-SA be formed, bent or molded?
Cold forms readily but with ~2× the force of 304 and strong springback; hot work 1100–1200 °C followed by mandatory solution anneal and water quench.
What is the maximum service temperature of 1.4659-SA?
1.4659-SA 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 1.4659-SA and 1.4659-CD?
SA is the default condition — standard supply condition for plate, sheet, bar and tube; maximum corrosion resistance and toughness. CD: bar stock for shafts, fasteners and valve trim where tighter tolerance and higher yield strength are needed. Yield strength is 460 MPa in SA versus 650 MPa in CD.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip (UNS S31266) — ASTM International (2023)
- EN 10088-2 / EN 10028-7 — Stainless steels, grade 1.4659 (X1CrNiMoCuNW24-22-6) — CEN (2017)
- UR SB8 / B66 superaustenitic stainless steel datasheet — Industeel (ArcelorMittal) (2021)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
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.