Stainless Steel 1.4658 HR-A
Finish state
EN 1.4658
Standard heavy plate condition for pressure vessels, tube sheets and seawater piping fabrication.
Values for the HR-A condition
Other 1.4658 tempers and conditions
1.4658 is listed in 5 conditions; see the grade overview at 1.4658.
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 |
HR-AThis page 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 HR-A?
1.4658 HR-A is 1.4658 supplied in the HR-A condition — standard heavy plate condition for pressure vessels, tube sheets and seawater piping fabrication. 1.4658 HR-A has a yield strength of 730 MPa (106 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 93% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi). 1.4658 HR-A 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). SA is the default condition FabDigit quotes; HR-A is available on request or by drawing note.
Advantages
- Good corrosion resistance — 90/100, better than 99% of stainless steel grades
- High strength — 730 MPa (106 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 HR-A properties
Typical room-temperature values for 1.4658 HR-A; 22 are specific to this condition. Other listed values are 1.4658 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4658 HR-A 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 HR-A has a yield strength of 730 MPa (106 ksi) and a tensile strength of 930 MPa (135 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 HR-A 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 HR-A 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 HR-A 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 HR-A's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability fair (50/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4658 HR-A
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.
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.
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 | — |
1.4658 HR-A — frequently asked
What is 1.4658 HR-A used for?
1.4658 HR-A 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 HR-A?
1.4658 HR-A has a typical yield strength of 730 MPa (106 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 93% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4658 HR-A 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 HR-A 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 HR-A?
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 HR-A 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 HR-A?
1.4658 HR-A 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.