Stainless Steel 1.4434-AT (Solution annealed)
Precip hard · default condition
EN 1.4434
Default condition for plate, bar, forgings and welded fabrication — maximum corrosion resistance and toughness.
Values for the AT condition
Other 1.4434 tempers and conditions
1.4434 is listed in 8 conditions; see the grade overview at 1.4434.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ATDefaultThis page Solution annealed | Default condition for plate, bar, forgings and welded fabrication — maximum corrosion resistance and toughness. | 330 | 620 | 45 | 190 HB | — |
As-welded deposit | Represents typical weld-joint properties for fabricated vessels — no post-weld solution treatment required thanks to ≤0.030 % C. | 350 | 590 | 30 | 200 HB | 2.2 % IACS |
Cold worked to Rm ≥ 700 MPa | Lightest standard strain-hardened bar/wire class when moderate extra strength is needed with good ductility. | 430 | 740 | 24 | 20 HRC | 2.3 % IACS |
Cold drawn | Standard bar stock for machined shafts, fittings and fasteners where higher yield and tighter tolerance are wanted. | 460 | 700 | 25 | 20 HRC | 2.3 % IACS |
Cold worked to Rm ≥ 800 MPa | Mid strain-hardened class for high-strength bolting and shafts in corrosive service. | 550 | 840 | 18 | 26 HRC | 2.3 % IACS |
Quarter hard | Cold-rolled strip class for springy clips and stiffened panels where forming is still needed. | 620 | 900 | 12 | 26 HRC | 2.3 % IACS |
Cold worked to Rm ≥ 900 MPa | Highest standard strain-hardened bar class; choose only where ductility and weldability are not critical. | 680 | 950 | 13 | 31 HRC | 2.3 % IACS |
Half hard | High-strength strip for flat springs, shims and diaphragms; forming limited to gentle bends. | 790 | 1,060 | 8 | 32 HRC | 2.3 % IACS |
What is 1.4434-AT?
1.4434-AT is 1.4434 in the AT condition — default condition for plate, bar, forgings and welded fabrication — maximum corrosion resistance and toughness. 1.4434-AT has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 57% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi). 1.4434-AT has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,390°C (2,534 °F).
Advantages
- Forms and bends easily — 78/100, better than 90% of stainless steel grades
- Readily welded — 85/100, better than 87% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- High embodied carbon — 5.6 kg CO₂/kg, worse than 83% of stainless steel grades
1.4434-AT properties
Typical room-temperature values for 1.4434-AT; 11 are specific to this condition. Other listed values are 1.4434 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4434-AT has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,390°C (2,534 °F).
Mechanical16
1.4434-AT has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 57% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4434-AT is rated for continuous service to 550°C (1,022 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
1.4434-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 1.4434-AT takes about 78 MJ of energy and emits 5.6 kg of CO₂ — more than 87% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
1.4434-AT's machinability is fair (36/100, better than 57% of stainless steel grades); weldability excellent (85/100); formability very good (78/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4434-AT
Is 1.4434 easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, high feed with constant engagement, ~20 % lower speeds than 316L and copious coolant to avoid glazing.
Can 1.4434 be welded?
Excellent by GTAW/GMAW/SMAW/SAW with 316LN or 19 12 3 L filler; no preheat and no PWHT needed, keep interpass below ~150 °C and use low-oxygen backing gas to preserve nitrogen and corrosion resistance.
Can 1.4434 be formed, bent or molded?
Good cold formability but high work-hardening rate and ~30 % higher forming loads than 316L; allow generous springback, hot work at 1150–900 °C then solution anneal at 1020–1120 °C with rapid cooling.
What surface finishes work on 1.4434?
Pickle and passivate (ASTM A967) after welding to remove heat tint; takes excellent mechanical polish and electropolish — no anodizing, plating only for special wear/appearance needs.
1.4434 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 for as-welded corrosion resistance | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.02 | 0.01 |
| Cr | 16.5 – 19.5 | 18 |
| Ni | 10.5 – 14 | 12.5 |
| Mohigher than 316L (2.0–2.5 %) — main pitting-resistance driver | 3 – 4 | 3.5 |
| Nsolid-solution strengthening + pitting resistance | 0.1 – 0.2 | 0.15 |
| Fe | balance | — |
1.4434-AT — frequently asked
What is 1.4434-AT used for?
1.4434-AT is typically used for offshore fasteners, seawater systems, chemical tanks and pulp & paper equipment. In short: higher-strength 316L; nitrogen-boosted pitting resistance; weldable without PWHT.
What is the yield strength of 1.4434-AT?
1.4434-AT has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 57% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is 1.4434-AT easy to machine?
Not especially — machinability is rated fair (36/100, better than 57% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, high feed with constant engagement, ~20 % lower speeds than 316L and copious coolant to avoid glazing.
Can 1.4434-AT be welded?
Yes — weldability is rated excellent (85/100). Excellent by GTAW/GMAW/SMAW/SAW with 316LN or 19 12 3 L filler; no preheat and no PWHT needed, keep interpass below ~150 °C and use low-oxygen backing gas to preserve nitrogen and corrosion resistance.
What surface finishes work on 1.4434-AT?
Pickle and passivate (ASTM A967) after welding to remove heat tint; takes excellent mechanical polish and electropolish — no anodizing, plating only for special wear/appearance needs.
Can 1.4434-AT be formed, bent or molded?
Good cold formability but high work-hardening rate and ~30 % higher forming loads than 316L; allow generous springback, hot work at 1150–900 °C then solution anneal at 1020–1120 °C with rapid cooling.
What is the maximum service temperature of 1.4434-AT?
1.4434-AT 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 1.4434-AT and 1.4434-CD?
AT is the default condition — default condition for plate, bar, forgings and welded fabrication — maximum corrosion resistance and toughness. CD: standard bar stock for machined shafts, fittings and fasteners where higher yield and tighter tolerance are wanted. Yield strength is 330 MPa in AT versus 460 MPa in CD.
Sources
- EN 10088-1/-2/-3 Stainless steels — list, sheet/plate and semi-finished/bar — CEN (2014)
- EN 10216-5 / EN 10217-7 Stainless steel tubes for pressure purposes — CEN (2013)
- ASTM A240 / A479 / A666 (UNS S31653) — ASTM International (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Austenitic stainless steel datasheets (316L / 316LN / 1.4434 class) — Outokumpu / Sandvik (2023)
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.