Stainless Steel 1.4490 +AT (Solution annealed)
Heat-treated state · default condition
EN 1.4490
Standard delivery condition for EN 10213/EN 10283 castings; maximum corrosion resistance and toughness — pick this unless the foundry offers HIP upgrading.
Values for the +AT condition
Other 1.4490 tempers and conditions
1.4490 is listed in 4 conditions; see the grade overview at 1.4490.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ATDefaultThis page Solution annealed | Standard delivery condition for EN 10213/EN 10283 castings; maximum corrosion resistance and toughness — pick this unless the foundry offers HIP upgrading. | 280 | 520 | 45 | 150 HB | — |
Spheroidize annealed | Only for non-corrosive, non-pressure hardware or rough stock to be heat treated later; interdendritic segregation and possible sigma/carbide give lower ductility and pitting resistance. | 290 | 510 | 30 | 160 HB | 2.3 % IACS |
Hot isostatically pressed then solution annealed and quenched | Choose for investment/precision castings needing closed microporosity: better fatigue, impact and radiographic quality at higher cost. | 290 | 545 | 50 | 155 HB | 2.3 % IACS |
+AT | Centrifugally cast pipe, rings and sleeves per ASTM A451/A452 practice; finer, denser wall structure gives slightly higher strength than static castings. | 300 | 550 | 42 | 160 HB | 2.3 % IACS |
What is 1.4490 +AT?
1.4490 +AT is 1.4490 heat treated to +AT — standard delivery condition for EN 10213/EN 10283 castings; maximum corrosion resistance and toughness — pick this unless the foundry offers HIP upgrading. 1.4490 +AT has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi). 1.4490 +AT has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Advantages
- Readily welded — 85/100, better than 87% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
- Low strength — 280 MPa (40.6 ksi), worse than 75% of stainless steel grades
1.4490 +AT properties
Typical room-temperature values for 1.4490 +AT; 13 are specific to this condition. Other listed values are 1.4490 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4490 +AT has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4490 +AT has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4490 +AT is rated for continuous service to 600°C (1,112 °F). It conducts heat at 14.5 W/m·K (8.38 BTU/hr·ft·°F), worse than 72% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4490 +AT conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 68% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4490 +AT takes about 55 MJ of energy and emits 4.6 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 70%.
Manufacturability7
1.4490 +AT's machinability is fair (40/100, better than 72% of stainless steel grades); weldability excellent (85/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4490 +AT
Is 1.4490 easy to machine?
Gummy and work-hardening like 316L: rigid setups, sharp positive-rake carbide, 60–110 m/min, heavy feed and flood coolant; avoid dwelling and expect abrasive skin/sand inclusions on unmachined castings.
Can 1.4490 be welded?
Excellent — GTAW/GMAW/SMAW with 316L or 317L filler, no preheat, interpass below ~150 °C; keep ferrite 3–10 FN in weld metal and re-solution-anneal after major repair welds on corrosion duty.
Can 1.4490 be formed, bent or molded?
Sand, investment and centrifugal casting all practical; wide 1400–1450 °C freezing range needs generous feeding and chills, and solution treatment plus water quench is mandatory for full corrosion performance.
What surface finishes work on 1.4490?
Pickle and passivate (nitric or citric) after grinding/welding to restore the passive film; shot blast with stainless or ceramic media only, and electropolishing gives good results where porosity is closed (HIP).
1.4490 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 — sensitisation resistance | ≤ 0.03 | 0.02 |
| Siraised for casting fluidity | ≤ 1.5 | 1 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 18 – 20 | 19 |
| Ni | 9 – 12 | 10.5 |
| Mopitting resistance | 2 – 2.5 | 2.3 |
| Nstrength + pitting; distinguishes CF3MN from CF3M | 0.1 – 0.2 | 0.15 |
| Fe | balance | — |
1.4490 +AT — frequently asked
What is 1.4490 +AT used for?
1.4490 +AT is typically used for valve bodies, pump casings and chemical process fittings. In short: cast 316L equivalent; molybdenum pitting resistance; weldable without post-weld anneal.
What is the yield strength of 1.4490 +AT?
1.4490 +AT has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 75% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4490 +AT easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Gummy and work-hardening like 316L: rigid setups, sharp positive-rake carbide, 60–110 m/min, heavy feed and flood coolant; avoid dwelling and expect abrasive skin/sand inclusions on unmachined castings.
Can 1.4490 +AT be welded?
Yes — weldability is rated excellent (85/100). Excellent — GTAW/GMAW/SMAW with 316L or 317L filler, no preheat, interpass below ~150 °C; keep ferrite 3–10 FN in weld metal and re-solution-anneal after major repair welds on corrosion duty.
What surface finishes work on 1.4490 +AT?
Pickle and passivate (nitric or citric) after grinding/welding to restore the passive film; shot blast with stainless or ceramic media only, and electropolishing gives good results where porosity is closed (HIP).
Can 1.4490 +AT be formed, bent or molded?
Sand, investment and centrifugal casting all practical; wide 1400–1450 °C freezing range needs generous feeding and chills, and solution treatment plus water quench is mandatory for full corrosion performance.
What is the maximum service temperature of 1.4490 +AT?
1.4490 +AT is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4490 +AT and 1.4490-AC?
+AT is the default condition — standard delivery condition for EN 10213/EN 10283 castings; maximum corrosion resistance and toughness — pick this unless the foundry offers HIP upgrading. AC: only for non-corrosive, non-pressure hardware or rough stock to be heat treated later; interdendritic segregation and possible sigma/carbide give lower ductility and pitting resistance. Yield strength is 280 MPa in +AT versus 290 MPa in AC.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A743/A743M — Castings, Iron-Chromium-Nickel, Corrosion Resistant (CF3M, CF3MN) — ASTM (2021)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook — Steel Founders' Society of America / ASM (1995)
- Outokumpu Corrosion Handbook / 316L austenitic data — Outokumpu (2021)
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.