Stainless Steel 1.4658
EN 1.4658
EN 1.4658 (X2CrNiMoCoN28-8-5-1, UNS S32808) is a cobalt-alloyed hyper duplex stainless — about 28% Cr, 8% Ni and 5% Mo with nitrogen — whose PREN exceeds conventional super duplex, giving a corrosion rating of 90.
Reference datasheet — 1.4658 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SA condition
1.4658 tempers and conditions
1.4658 is supplied in 5 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-welded deposit | Typical joint properties when solution annealing after welding is impossible; expect lower toughness and CPT than base metal. | 700 | 900 | 22 | 27 HRC | 1.8 % IACS |
Forged + SA | For valve bodies, flanges and subsea forgings; heavy sections need rapid quench to avoid sigma phase in the core. | 720 | 920 | 28 | 28 HRC | 1.8 % IACS |
hot rolled, solution annealed and pickled plate (1D finish) | Standard heavy plate condition for pressure vessels, tube sheets and seawater piping fabrication. | 730 | 930 | 30 | 27 HRC | 1.8 % IACS |
SADefault Solution annealed and quenched | Standard supply condition for plate, seamless tube and bar; optimum phase balance and corrosion resistance. | 750 | 950 | 30 | 28 HRC | — |
cold drawn / cold pilgered after final solution anneal | Choose for umbilical, instrumentation and hydraulic tubing where higher strength and tight tolerance matter more than ductility. | 950 | 1,100 | 18 | 34 HRC | — |
What is 1.4658?
EN 1.4658 (X2CrNiMoCoN28-8-5-1, UNS S32808) is a cobalt-alloyed hyper duplex stainless — about 28% Cr, 8% Ni and 5% Mo with nitrogen — whose PREN exceeds conventional super duplex, giving a corrosion rating of 90. Engineers specify it for extreme chloride and high-temperature seawater duty at 750 MPa yield, 950 MPa tensile, 30% elongation and about 275 HB (28 HRC), supplied as solution-annealed and cold-drawn bar, hot-rolled and forged product and as-welded assemblies. Cost and lead time are high and machinability is poor (score 22); service is limited to about 300 °C, with 1.4410 (2507) the usual fallback where the extra PREN is not required. 1.4658 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,330°C (2,426 °F). 1.4658 has a yield strength of 750 MPa (109 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 93% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is 1.4658 used for?
- deep subsea flowlines
- desalination high-temperature units
- extreme marine environments
Advantages
- Good corrosion resistance — 90/100, better than 99% of stainless steel grades
- High strength — 750 MPa (109 ksi), better than 93% of stainless steel grades
Limitations
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Low electrical conductivity — 1.8 % IACS, worse than 87% of stainless steel grades
- Poor heat conductor — 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 85% of stainless steel grades
- Difficult to weld — 50/100, worse than 77% of stainless steel grades
1.4658 properties
Typical room-temperature values for 1.4658-SA; bars are the position among stainless steel grades.
Physical3
1.4658 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,330°C (2,426 °F).
Mechanical16
1.4658 has a yield strength of 750 MPa (109 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 93% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4658 is rated for continuous service to 300°C (572 °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 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
1.4658 conducts electricity at 1.8 % IACS, worse than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4658 takes about 72 MJ of energy and emits 5.2 kg of CO₂ — more than 83% of stainless steel grades. Typical recycled content is 35%.
Manufacturability7
1.4658's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability fair (50/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 1.4658 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4658
Is 1.4658 easy to machine?
Very tough and work-hardening — use rigid setups, sharp coated carbide, low speeds (~40–60 m/min), heavy positive feeds and copious coolant to avoid glazing.
Can 1.4658 be welded?
GTAW/GMAW/SMAW with matching or Ni-overalloyed super duplex filler, Ar+2%N₂ backing, interpass ≤100 °C and heat input roughly 0.2–1.0 kJ/mm; solution anneal + water quench after welding whenever possible.
Can 1.4658 be formed, bent or molded?
Cold forming needs ~2× the load of 316L with large springback; hot work 1000–1200 °C followed by immediate solution anneal and quench — never leave the alloy in the 600–1000 °C sigma range.
1.4658 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 precipitation | ≤ 0.03 | 0.02 |
| Si | ≤ 0.5 | 0.3 |
| Mn | ≤ 1.5 | 0.8 |
| P | ≤ 0.04 | — |
| S | ≤ 0.01 | — |
| Cr | 26 – 29 | 27.5 |
| Ni | 5.5 – 9.5 | 6.8 |
| Mo | 4 – 5 | 4.8 |
| Costabilises austenite, retards intermetallic precipitation | 0.5 – 2 | 1 |
| Nmain contributor to PREN ≈ 49 | 0.3 – 0.5 | 0.4 |
| Cuoptional/residual | ≤ 1 | 0.3 |
| Fe | balance | — |
What surface finishes work on 1.4658?
Pickle and passivate (HNO₃-HF) after hot work or welding to restore the passive film; polishes well to Ra <0.4 µm; do not paint or plate for corrosion purposes.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 1.4658 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- X2CrNiMoCoN28-8-5-1
- Similar grades
- S32808
How much does 1.4658 cost?
1.4658 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1.4658 — frequently asked
What is 1.4658 used for?
1.4658 is typically used for deep subsea flowlines, desalination high-temperature units and extreme marine environments. In short: highest-PREN duplex family; beyond super duplex chloride limits; hardest duplex to machine.
What is the yield strength of 1.4658?
1.4658 has a typical yield strength of 750 MPa (109 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 93% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4658 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of stainless steel grades). Very tough and work-hardening — use rigid setups, sharp coated carbide, low speeds (~40–60 m/min), heavy positive feeds and copious coolant to avoid glazing.
Can 1.4658 be welded?
With care — weldability is rated fair (50/100). GTAW/GMAW/SMAW with matching or Ni-overalloyed super duplex filler, Ar+2%N₂ backing, interpass ≤100 °C and heat input roughly 0.2–1.0 kJ/mm; solution anneal + water quench after welding whenever possible.
What surface finishes work on 1.4658?
Pickle and passivate (HNO₃-HF) after hot work or welding to restore the passive film; polishes well to Ra <0.4 µm; do not paint or plate for corrosion purposes.
Can 1.4658 be formed, bent or molded?
Cold forming needs ~2× the load of 316L with large springback; hot work 1000–1200 °C followed by immediate solution anneal and quench — never leave the alloy in the 600–1000 °C sigma range.
What is the maximum service temperature of 1.4658?
1.4658 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 1.4658-SA and 1.4658 SA-CD?
SA is the default condition — standard supply condition for plate, seamless tube and bar; optimum phase balance and corrosion resistance. SA-CD: choose for umbilical, instrumentation and hydraulic tubing where higher strength and tight tolerance matter more than ductility. Yield strength is 750 MPa in SA versus 950 MPa in SA-CD.
How much does 1.4658 cost?
1.4658 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10088-1/-2/-3 Stainless steels – list of grades, sheet/plate and bar — CEN (2014)
- Sandvik SAF 2707 HD hyper-duplex stainless steel (UNS S32707, EN 1.4658) — Alleima/Sandvik Materials Technology (2022)
- ASTM A789 / A790 / A240 duplex stainless tube, pipe and plate — ASTM International (2021)
- ASM Handbook Vol.1 – Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Practical Guidelines for the Fabrication of Duplex Stainless Steels — International Molybdenum Association (IMOA) (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.