Stainless Steel 1.4588
EN 1.4588
1.4588 (GX2NiCrMoCuN25-20-6, ASTM A351 CK3MCuN, UNS J93254) is a 6 % Mo, copper- and nitrogen-alloyed cast superaustenitic stainless steel, supplied solution annealed (SA), SA+HIP, SA-HW or as-cast.
Reference datasheet — 1.4588 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
1.4588 tempers and conditions
1.4588 is supplied in 4 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SA | Heavy-section castings where slower quench rate and coarser dendrites give slightly lower ductility/toughness at the same specified minima. | 290 | 565 | 38 | 165 HB | 2 % IACS |
SADefault Solution annealed ~1120–1180 °C + rapid water quench | Standard and essentially only supply condition; required to dissolve interdendritic sigma/chi and secure full corrosion performance. | 300 | 585 | 45 | 170 HB | 2 % IACS |
Spheroidize annealed | Only for rough/non-corrosion-critical hardware; interdendritic sigma and Mo segregation sharply reduce pitting resistance and toughness. | 300 | 540 | 20 | 14 HRC | 2 % IACS |
Hot isostatically pressed then solution annealed and quenched | Choose for pressure-retaining or radiographically critical pump/valve castings where microporosity must be closed and ductility/toughness maximised. | 310 | 610 | 50 | 170 HB | 2 % IACS |
What is 1.4588?
1.4588 (GX2NiCrMoCuN25-20-6, ASTM A351 CK3MCuN, UNS J93254) is a 6 % Mo, copper- and nitrogen-alloyed cast superaustenitic stainless steel, supplied solution annealed (SA), SA+HIP, SA-HW or as-cast. It gives the highest strength in this cast group — 300 MPa yield, 585 MPa tensile, 45 % elongation and 170 HB (88 HRB) — for severe chloride and acid duty in pump and valve castings. Service is limited to 400 °C, machinability is about 25, and parts must be re-solution annealed after casting or major weld repair; 1.4584 (CN7M) is the cheaper choice where chlorides are absent. 1.4588 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,320°C (2,408 °F). 1.4588 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 68% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
What is 1.4588 used for?
- Desalination pump castings
- Chemical process valve bodies
- Seawater pump impellers and casings
- Flue gas desulfurization scrubber parts
- Offshore firewater pump components
- Pulp bleach plant fittings
Advantages
- Good corrosion resistance — 84/100, better than 91% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Poor heat conductor — 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades
- High embodied carbon — 6.5 kg CO₂/kg, worse than 93% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
1.4588 properties
Typical room-temperature values for 1.4588-SA; bars are the position among stainless steel grades.
Physical3
1.4588 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Mechanical16
1.4588 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 68% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4588 is rated for continuous service to 400°C (752 °F). It conducts heat at 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades. Thermal expansion is 14.6 µm/m·K (8.11 µin/in·°F).
Electrical3
1.4588 conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (84/100), better than 91% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4588 takes about 85 MJ of energy and emits 6.5 kg of CO₂ — more than 92% of stainless steel grades. Typical recycled content is 40%.
Manufacturability8
1.4588's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability good (60/100); formability poor (30/100).
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. 1.4588 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4588
Is 1.4588 easy to machine?
Machine like AL-6XN/904L: rigid setups, sharp positive-rake carbide, heavy flood coolant, low speed with high feed to avoid work hardening and glazing; expect ~30 % of 1212 rates.
Can 1.4588 be welded?
GTAW/GMAW with overalloyed Ni-base filler (ERNiCrMo-3/-4) to compensate Mo dilution; low heat input, no preheat, interpass < 150 °C, and no post-weld stress relief in the 500–900 °C range.
Can 1.4588 be formed, bent or molded?
Supplied as sand/investment/centrifugal castings — design generous fillets and directional feeding for the wide freezing range; always re-solution anneal and water quench after casting, HIP or major repair welding.
1.4588 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/sigma precipitation | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.6 |
| MnA351 CK3MCuN limits Mn to 1.20 max | ≤ 2 | 1 |
| P | ≤ 0.05 | |
| S | ≤ 0.01 | |
| Cr | 19 – 21 | 20 |
| NiEN 1.4588 is high-Ni; A351 CK3MCuN is 17.5–19.5 Ni | 24 – 26 | 25 |
| Mo | 6 – 7 | 6.5 |
| CuA351 CK3MCuN: 0.50–1.00 Cu | 1 – 2 | 1.5 |
| N | 0.15 – 0.25 | 0.2 |
| Fe | balance |
What surface finishes work on 1.4588?
Pickle in HNO₃-HF then passivate to restore the Cr-Mo-N film; grind out weld heat tint fully, and avoid carbon-steel contact tooling to prevent iron contamination and later pitting.
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 1.4588 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- GX2NiCrMoCuN25-20-6
- Similar grades
- A351 CK3MCuNJ93254
How much does 1.4588 cost?
1.4588 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.
1.4588 — frequently asked
What is 1.4588 used for?
1.4588 is typically used for desalination pump castings, chemical process valve bodies, seawater pump impellers and casings, flue gas desulfurization scrubber parts, offshore firewater pump components and pulp bleach plant fittings. In short: strongest cast superaustenitic here; 6Mo chloride resistance; desalination pump grade.
What is the yield strength of 1.4588?
1.4588 has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 68% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4588 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine like AL-6XN/904L: rigid setups, sharp positive-rake carbide, heavy flood coolant, low speed with high feed to avoid work hardening and glazing; expect ~30 % of 1212 rates.
Can 1.4588 be welded?
Yes — weldability is rated good (60/100). GTAW/GMAW with overalloyed Ni-base filler (ERNiCrMo-3/-4) to compensate Mo dilution; low heat input, no preheat, interpass < 150 °C, and no post-weld stress relief in the 500–900 °C range.
What surface finishes work on 1.4588?
Pickle in HNO₃-HF then passivate to restore the Cr-Mo-N film; grind out weld heat tint fully, and avoid carbon-steel contact tooling to prevent iron contamination and later pitting.
Can 1.4588 be formed, bent or molded?
Supplied as sand/investment/centrifugal castings — design generous fillets and directional feeding for the wide freezing range; always re-solution anneal and water quench after casting, HIP or major repair welding.
What is the maximum service temperature of 1.4588?
1.4588 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 1.4588-SA and 1.4588 SA-HW?
SA is the default condition — standard and essentially only supply condition; required to dissolve interdendritic sigma/chi and secure full corrosion performance. SA-HW: heavy-section castings where slower quench rate and coarser dendrites give slightly lower ductility/toughness at the same specified minima. Yield strength is 300 MPa in SA versus 290 MPa in SA-HW.
How much does 1.4588 cost?
1.4588 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 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CK3MCuN, J93254) — ASTM (2023)
- ASTM A743/A744 — Corrosion-resistant iron-chromium-nickel castings — ASTM (2021)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- 6 % Mo superaustenitic stainless steel data (254 SMO / AL-6XN class) — Outokumpu / ATI (2022)
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.