Stainless Steel 1.4508-ST (Solution annealed)
Heat-treated state · default condition
EN 1.4508 · UNS J92999 · ASTM CG3M
The only standard supply condition for this grade; maximises corrosion resistance and toughness by dissolving carbides and sigma-forming phases.
Values for the ST condition
Other 1.4508 tempers and conditions
1.4508 is listed in 4 conditions; see the grade overview at 1.4508.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-welded deposit | Condition of a low-carbon N-alloyed casting after production weld repair; usable without re-annealing because C ≤0.03 % prevents sensitisation, but ferrite/sigma control and NDT are required. | 285 | 520 | 32 | 180 HB | 2.2 % IACS |
STDefaultThis page Solution annealed | The only standard supply condition for this grade; maximises corrosion resistance and toughness by dissolving carbides and sigma-forming phases. | 290 | 540 | 40 | 165 HB | 2.2 % IACS |
Hot isostatically pressed then solution annealed | Choose for pressure-retaining or fatigue-critical castings where shrinkage microporosity must be closed; gives higher ductility, toughness and fatigue life. | 300 | 560 | 48 | 165 HB | 2.2 % IACS |
Centrifugally cast, solution annealed | Pick for tubes, sleeves and rings: the dense, directionally solidified wall gives slightly higher strength and better soundness than static sand casting. | 310 | 570 | 38 | 170 HB | 2.2 % IACS |
What is 1.4508-ST?
1.4508-ST is 1.4508 heat treated to ST — the only standard supply condition for this grade; maximises corrosion resistance and toughness by dissolving carbides and sigma-forming phases. 1.4508-ST has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 72% of stainless steel grades. Elongation at break is 40% and the elastic modulus is 195 GPa (28.3 Msi). 1.4508-ST has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Advantages
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Hard to polish — 60/100, worse than 80% of stainless steel grades
1.4508-ST properties
Typical room-temperature values for 1.4508-ST; 23 are specific to this condition. Other listed values are 1.4508 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4508-ST has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4508-ST has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 72% of stainless steel grades. Elongation at break is 40% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4508-ST is rated for continuous service to 550°C (1,022 °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 µm/m·K (8.89 µin/in·°F).
Electrical3
1.4508-ST conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4508-ST takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
1.4508-ST's machinability is fair (35/100, better than 51% of stainless steel grades); weldability very good (80/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4508-ST
Is 1.4508 easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy feed to stay under the hardened skin, and flood coolant; expect ~40 % of AISI 1212.
Can 1.4508 be welded?
Readily welded by GTAW/SMAW/FCAW with 316L or 316LN filler (E316LN/ER316LNi); no post-weld anneal needed thanks to ≤0.03 % C, keep interpass <150 °C and heat input low to limit sigma phase.
Can 1.4508 be formed, bent or molded?
Supplied as sand, investment or centrifugal castings; wide freezing range demands good risering and chills, and nitrogen levels must be held to avoid gas porosity.
What surface finishes work on 1.4508?
Pickle and passivate (ASTM A967) or electropolish after machining; shot blasting alone leaves an iron-contaminated surface that rusts.
1.4508 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 |
|---|---|---|
| Cextra-low carbon, avoids sensitisation | ≤ 0.03 | 0.02 |
| Sicasting fluidity | ≤ 1.5 | 1 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 18 – 20 | 19 |
| Ni | 9 – 12 | 11 |
| Mochloride pitting resistance | 2 – 2.5 | 2.3 |
| Nsolid-solution strengthening, austenite stabiliser | 0.1 – 0.2 | 0.15 |
| Fe | balance | — |
1.4508-ST — frequently asked
What is 1.4508-ST used for?
1.4508-ST is typically used for pump casings, valve bodies, chemical processing equipment and marine hardware. In short: nitrogen-strengthened cast 316L; 40% elongation as cast; weld-repairable without anneal.
What is the yield strength of 1.4508-ST?
1.4508-ST has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 72% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4508-ST easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy feed to stay under the hardened skin, and flood coolant; expect ~40 % of AISI 1212.
Can 1.4508-ST be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/SMAW/FCAW with 316L or 316LN filler (E316LN/ER316LNi); no post-weld anneal needed thanks to ≤0.03 % C, keep interpass <150 °C and heat input low to limit sigma phase.
What surface finishes work on 1.4508-ST?
Pickle and passivate (ASTM A967) or electropolish after machining; shot blasting alone leaves an iron-contaminated surface that rusts.
Can 1.4508-ST be formed, bent or molded?
Supplied as sand, investment or centrifugal castings; wide freezing range demands good risering and chills, and nitrogen levels must be held to avoid gas porosity.
What is the maximum service temperature of 1.4508-ST?
1.4508-ST is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4508-ST and 1.4508 CENT-ST?
ST is the default condition — the only standard supply condition for this grade; maximises corrosion resistance and toughness by dissolving carbides and sigma-forming phases. CENT-ST: pick for tubes, sleeves and rings: the dense, directionally solidified wall gives slightly higher strength and better soundness than static sand casting. Yield strength is 290 MPa in ST versus 310 MPa in CENT-ST.
Sources
- EN 10213-4 / EN 10213 — Steel castings for pressure purposes, austenitic and austenitic-ferritic grades — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A351/A351M — Castings, austenitic, for pressure-containing parts (CG3M, J92999) — ASTM International (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast corrosion-resistant steels) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Stainless steel casting alloy datasheets (CF3M/CG3M/1.4408-1.4508 family) — European steel foundries (2022)
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.