Stainless Steel 1.4557
EN 1.4557 · UNS J93254 · ASTM A351 CK3MCuN
1.4557 (GX2CrNiMoCuN20-18-6, A351 CK3MCuN, J93254) is a cast superaustenitic stainless steel matching the composition of wrought 254SMO, with high molybdenum plus copper and nitrogen.
Reference datasheet — 1.4557 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
1.4557 tempers and conditions
1.4557 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 |
|---|---|---|---|---|---|---|
SADefault Solution annealed ~1150–1200 °C, water quenched | Standard supply condition for all A351/EN 10283 CK3MCuN castings; required to dissolve Mo-rich segregation and sigma/chi phases before service. | 295 | 600 | 45 | 175 HB | — |
Spheroidize annealed | Intermediate/rough-machining condition only — interdendritic Mo segregation and sigma/chi phase sharply reduce ductility and pitting resistance; never use in corrosive service. | 300 | 540 | 18 | 200 HB | 2 % IACS |
Hot isostatically pressed then solution annealed and quenched | Choose for pressure-retaining or high-cycle parts where shrinkage porosity must be closed — best ductility, toughness and NDT/radiographic quality. | 305 | 620 | 50 | 180 HB | 2 % IACS |
Centrifugally cast, solution annealed | Pick for seawater and FGD piping/sleeves — directional solidification gives a finer, denser wall than static castings. | 310 | 620 | 40 | 180 HB | 2 % IACS |
What is 1.4557?
1.4557 (GX2CrNiMoCuN20-18-6, A351 CK3MCuN, J93254) is a cast superaustenitic stainless steel matching the composition of wrought 254SMO, with high molybdenum plus copper and nitrogen. It gives exceptional resistance to chloride pitting and crevice corrosion (score 86) in seawater and desalination duty, and is supplied as solution-annealed sand or centrifugal castings, with HIP available. Default values are 295 MPa yield, 600 MPa tensile, 45 % elongation and 175 HB (88 HRB), with service to 400 °C. Machinability is the lowest in this group (score 22), nickel-base filler is required and cost is high; 1.4451 is a lower-cost alternative. 1.4557 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,325°C (2,417 °F). 1.4557 has a yield strength of 295 MPa (42.8 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 70% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
What is 1.4557 used for?
- seawater pump casings
- desalination equipment
- offshore valve bodies
Advantages
- Good corrosion resistance — 86/100, better than 94% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
- High embodied carbon — 6.5 kg CO₂/kg, worse than 93% of stainless steel grades
- Limited formability — 20/100, worse than 86% 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
1.4557 properties
Typical room-temperature values for 1.4557-SA; bars are the position among stainless steel grades.
Physical3
1.4557 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,325°C (2,417 °F).
Mechanical16
1.4557 has a yield strength of 295 MPa (42.8 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 70% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4557 is rated for continuous service to 400°C (752 °F). It conducts heat at 13.5 W/m·K (7.8 BTU/hr·ft·°F), worse than 83% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4557 conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (86/100), better than 94% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4557 takes about 90 MJ of energy and emits 6.5 kg of CO₂ — more than 94% of stainless steel grades. Typical recycled content is 50%.
Manufacturability8
1.4557's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability good (65/100); formability poor (20/100).
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. 1.4557 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4557
Is 1.4557 easy to machine?
Tough, gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, heavy feed with low-to-moderate speed (~30–60 m/min), plenty of high-pressure coolant, and never dwell in the cut.
Can 1.4557 be welded?
Weld with over-alloyed Ni-base fillers (ERNiCrMo-3/-4 or ENiCrMo-3), low heat input, interpass <150 °C, no preheat; autogenous or matching-filler welds lose pitting resistance and generally need re-solution treatment.
Can 1.4557 be formed, bent or molded?
Foundry grade: wide freezing range means generous feeding, chills and risers; solution anneal at 1150–1200 °C with rapid water quench is mandatory to dissolve sigma/chi and restore corrosion performance.
1.4557 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 |
|---|---|---|
| CEN 10283 allows ≤0.03 | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.6 |
| Mn | ≤ 1.2 | 0.8 |
| P | ≤ 0.05 | |
| S | ≤ 0.01 | |
| CrEN: 19.0–21.0 | 19.5 – 20.5 | 20 |
| Ni | 17.5 – 19.5 | 18.5 |
| Mo | 6 – 7 | 6.5 |
| Cu | 0.5 – 1 | 0.7 |
| NEN: 0.15–0.25 | 0.18 – 0.24 | 0.21 |
| Fe | balance |
What surface finishes work on 1.4557?
Pickle (HNO₃-HF) and passivate per ASTM A967 or electropolish after all welding/grinding; avoid iron contamination from carbon-steel tooling and blasting media.
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 1.4557 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J93254
- ASTM
- A351 CK3MCuN
- EN / DIN / Werkstoff-Nr.
- GX2CrNiMoCuN20-18-6
How much does 1.4557 cost?
1.4557 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.
1.4557 — frequently asked
What is 1.4557 used for?
1.4557 is typically used for seawater pump casings, desalination equipment and offshore valve bodies. In short: cast 254SMO equivalent; top chloride pitting resistance; hardest grade to machine.
What is the yield strength of 1.4557?
1.4557 has a typical yield strength of 295 MPa (42.8 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 70% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4557 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of stainless steel grades). Tough, gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, heavy feed with low-to-moderate speed (~30–60 m/min), plenty of high-pressure coolant, and never dwell in the cut.
Can 1.4557 be welded?
Yes — weldability is rated good (65/100). Weld with over-alloyed Ni-base fillers (ERNiCrMo-3/-4 or ENiCrMo-3), low heat input, interpass <150 °C, no preheat; autogenous or matching-filler welds lose pitting resistance and generally need re-solution treatment.
What surface finishes work on 1.4557?
Pickle (HNO₃-HF) and passivate per ASTM A967 or electropolish after all welding/grinding; avoid iron contamination from carbon-steel tooling and blasting media.
Can 1.4557 be formed, bent or molded?
Foundry grade: wide freezing range means generous feeding, chills and risers; solution anneal at 1150–1200 °C with rapid water quench is mandatory to dissolve sigma/chi and restore corrosion performance.
What is the maximum service temperature of 1.4557?
1.4557 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 1.4557-SA and 1.4557 CENT-SA?
SA is the default condition — standard supply condition for all A351/EN 10283 CK3MCuN castings; required to dissolve Mo-rich segregation and sigma/chi phases before service. CENT-SA: pick for seawater and FGD piping/sleeves — directional solidification gives a finer, denser wall than static castings. Yield strength is 295 MPa in SA versus 310 MPa in CENT-SA.
How much does 1.4557 cost?
1.4557 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
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CK3MCuN) — ASTM International (2023)
- ASTM A743/A744 — Corrosion-Resistant Iron-Chromium-Nickel Castings — ASTM International (2021)
- EN 10283 — Corrosion resistant steel castings (GX2CrNiMoCuN20-18-6, 1.4557) — CEN (2019)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- 254 SMO / 6Mo austenitic stainless steel data sheet (physical & corrosion data for equivalent composition) — Outokumpu / Sandvik (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.