Stainless Steel 1.4518-AC (Spheroidize annealed)
Heat-treated state
EN 1.4518 · UNS J92800 · ASTM CF3M
Only for non-critical, non-corrosive structural castings; interdendritic segregation and possible sigma/carbide give lower ductility and corrosion resistance.
Values for the AC condition
Other 1.4518 tempers and conditions
1.4518 is listed in 5 conditions; see the grade overview at 1.4518.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ATDefault solution annealed 1040–1120 °C and water quenched | Standard delivery condition for all pressure-retaining and corrosion-service castings; maximum corrosion resistance and ductility. | 260 | 530 | 48 | 150 HB | 2.3 % IACS |
Solution annealed, weld-repaired (as-welded, no re-anneal) | Practical condition for foundry-repaired castings — the ≤0.03 % C level keeps the heat-affected zone free of sensitisation without a second solution treatment. | 265 | 520 | 40 | 160 HB | 2.3 % IACS |
hot isostatically pressed then solution annealed | Choose for pressure-critical or fatigue-loaded castings where internal microporosity must be closed (subsea, nuclear, high-cycle pump parts). | 270 | 545 | 55 | 150 HB | 2.3 % IACS |
Centrifugally cast, solution annealed | For cylindrical bodies, sleeves and pipe (ASTM A451/A452-style supply) where a dense, porosity-free wall and machinable bore are needed. | 270 | 545 | 45 | 155 HB | 2.3 % IACS |
ACThis page Spheroidize annealed | Only for non-critical, non-corrosive structural castings; interdendritic segregation and possible sigma/carbide give lower ductility and corrosion resistance. | 275 | 520 | 30 | 160 HB | 2.3 % IACS |
What is 1.4518-AC?
1.4518-AC is 1.4518 heat treated to AC — only for non-critical, non-corrosive structural castings; interdendritic segregation and possible sigma/carbide give lower ductility and corrosion resistance. 1.4518-AC has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 195 GPa (28.3 Msi). 1.4518-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,385°C (2,525 °F). AT is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Limited formability — 18/100, worse than 89% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- Low strength — 275 MPa (39.9 ksi), worse than 77% of stainless steel grades
1.4518-AC properties
Typical room-temperature values for 1.4518-AC; 22 are specific to this condition. Other listed values are 1.4518 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4518-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,385°C (2,525 °F).
Mechanical16
1.4518-AC has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4518-AC is rated for continuous service to 450°C (842 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
1.4518-AC conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4518-AC takes about 55 MJ of energy and emits 5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
1.4518-AC's machinability is fair (36/100, better than 57% of stainless steel grades); weldability very good (74/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4518-AC
Is 1.4518 easy to machine?
Gummy and work-hardening: use rigid setups, sharp positive-rake carbide, 60–110 m/min cutting speed, heavy feed to cut under the hardened skin, and flood coolant; remove the casting skin/sand inclusions in a first sacrificial pass.
Can 1.4518 be welded?
Excellent — GTAW/SMAW/FCAW with 316L or ER316LSi filler (309L for dissimilar joints), low heat input, interpass ≤150 °C; no preheat and no post-weld solution anneal needed for corrosion service thanks to ≤0.03 % C.
Can 1.4518 be formed, bent or molded?
Cast only — good fluidity but a wide freezing range demands generous risering, chills at heavy sections and controlled ferrite (3–15 FN) to avoid hot tearing and microporosity; HIP if leak-tightness is critical.
What surface finishes work on 1.4518?
Grit-blast then pickle/passivate per ASTM A967 (never use carbon-steel media or tooling); electropolishing gives hygienic Ra <0.8 µm surfaces; do not anodize.
1.4518 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 |
|---|---|---|
| Csuper-low carbon, prevents sensitisation | ≤ 0.03 | 0.02 |
| SiEN limit; ASTM CF3M ≤1.50 | ≤ 1.5 | 1 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | 0.03 |
| SEN 10283 typically ≤0.020 | ≤ 0.03 | 0.02 |
| Cr | 18 – 20 | 19 |
| Ni | 9 – 13 | 11 |
| Modesignation -3 reflects upper-Mo aim | 2 – 3 | 2.7 |
| Nresidual; not intentionally alloyed | ≤ 0.2 | 0.05 |
| Fe | balance | — |
1.4518-AC — frequently asked
What is 1.4518-AC used for?
1.4518-AC is typically used for valve bodies, pump housings, food and chemical processing equipment and marine fittings. In short: cast 316L equivalent; weldable without post-anneal; high-ductility stainless casting.
What is the yield strength of 1.4518-AC?
1.4518-AC has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 77% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4518-AC easy to machine?
Not especially — machinability is rated fair (36/100, better than 57% of stainless steel grades). Gummy and work-hardening: use rigid setups, sharp positive-rake carbide, 60–110 m/min cutting speed, heavy feed to cut under the hardened skin, and flood coolant; remove the casting skin/sand inclusions in a first sacrificial pass.
Can 1.4518-AC be welded?
Yes — weldability is rated very good (74/100). Excellent — GTAW/SMAW/FCAW with 316L or ER316LSi filler (309L for dissimilar joints), low heat input, interpass ≤150 °C; no preheat and no post-weld solution anneal needed for corrosion service thanks to ≤0.03 % C.
What surface finishes work on 1.4518-AC?
Grit-blast then pickle/passivate per ASTM A967 (never use carbon-steel media or tooling); electropolishing gives hygienic Ra <0.8 µm surfaces; do not anodize.
Can 1.4518-AC be formed, bent or molded?
Cast only — good fluidity but a wide freezing range demands generous risering, chills at heavy sections and controlled ferrite (3–15 FN) to avoid hot tearing and microporosity; HIP if leak-tightness is critical.
What is the maximum service temperature of 1.4518-AC?
1.4518-AC is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4518-AT and 1.4518-AC?
AT is the default condition — standard delivery condition for all pressure-retaining and corrosion-service castings; maximum corrosion resistance and ductility. AC: only for non-critical, non-corrosive structural castings; interdendritic segregation and possible sigma/carbide give lower ductility and corrosion resistance. Yield strength is 260 MPa in AT versus 275 MPa in AC.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CF3M) — ASTM (2023)
- ASTM A743/A744 — Corrosion-Resistant Iron-Chromium-Nickel Castings — ASTM (2021)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- GB/T 2100 / ZG022Cr19Ni10Mo3 general purpose corrosion-resisting steel castings — SAC (2017)
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.