Stainless Steel 1.4537 HR-AT
Finish state
EN 1.4537 · UNS N08935 · also Alloy 32
HR-AT = hot rolled + solution annealed plate
Heavy plate for pressure vessels, scrubbers and acid tanks; same metallurgy as AT with hot-rolled/pickled surface.
Values for the HR-AT condition
Other 1.4537 tempers and conditions
1.4537 is listed in 6 conditions; see the grade overview at 1.4537.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged + solution annealed (flanges, valve bodies, fittings) | Heavy forged sections for valves, pump casings and flanges; check through-thickness annealing quality. | 335 | 680 | 42 | 180 HB | 1.7 % IACS |
HR-ATThis page Hot rolled + solution annealed plate | Heavy plate for pressure vessels, scrubbers and acid tanks; same metallurgy as AT with hot-rolled/pickled surface. | 340 | 690 | 45 | 180 HB | 1.7 % IACS |
ATDefault Solution annealed and quenched (1100–1150 °C, water quenched), pickled | Standard supply condition for plate, sheet, tube and forgings — maximum corrosion resistance and ductility. | 350 | 700 | 45 | 185 HB | — |
Cold rolled + annealed sheet, 2B finish | Thin sheet/strip for linings, bellows and heat-exchanger plates where a smooth bright surface is needed. | 360 | 720 | 43 | 190 HB | 1.7 % IACS |
As-welded deposit | Fabricated joints without post-weld solution anneal — expect somewhat lower pitting resistance in the weld metal unless Ni-base filler is used. | 380 | 670 | 32 | 200 HB | 1.6 % IACS |
Cold drawn | Bar stock for pump shafts, fasteners and valve stems needing higher yield strength and tight tolerance. | 560 | 820 | 25 | 24 HRC | 1.7 % IACS |
What is 1.4537 HR-AT?
1.4537 HR-AT is 1.4537 supplied in the HR-AT condition — heavy plate for pressure vessels, scrubbers and acid tanks; same metallurgy as AT with hot-rolled/pickled surface. 1.4537 HR-AT has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi). 1.4537 HR-AT has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,320°C (2,408 °F). AT is the default condition FabDigit quotes; HR-AT is available on request or by drawing note.
Advantages
- Good corrosion resistance — 88/100, better than 97% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
- Forms and bends easily — 68/100, better than 75% of stainless steel grades
Limitations
- Poor heat conductor — 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- High embodied carbon — 5.6 kg CO₂/kg, worse than 83% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
1.4537 HR-AT properties
Typical room-temperature values for 1.4537 HR-AT; 22 are specific to this condition. Other listed values are 1.4537 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4537 HR-AT has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Mechanical14
1.4537 HR-AT has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal5
1.4537 HR-AT is rated for continuous service to 400°C (752 °F). It conducts heat at 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades. Thermal expansion is 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
1.4537 HR-AT conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 97% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4537 HR-AT takes about 62 MJ of energy and emits 5.6 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
1.4537 HR-AT's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability very good (70/100); formability good (68/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4537 HR-AT
Is 1.4537 easy to machine?
Very gummy and strongly work hardening — use rigid setups, positive-rake sharp carbide/coated inserts, heavy feed with low-to-moderate speed (≈30–60 m/min turning), high-pressure coolant, and never dwell in the cut.
Can 1.4537 be welded?
GTAW/GMAW/SMAW with over-alloyed Ni-base filler (ERNiCrMo-3/-4 or ERNiCrMo-13) to avoid Mo segregation; keep interpass ≤100–150 °C, no preheat, low heat input, back-purge with Ar (+N2) and pickle/passivate after welding.
Can 1.4537 be formed, bent or molded?
Cold forms well but needs ≈50 % more force than 304 and generous springback allowance; hot work 1150–1200 °C followed by mandatory solution anneal 1100–1150 °C with rapid water quench.
What surface finishes work on 1.4537?
Pickle in HNO3-HF and passivate (ASTM A967) after hot work or welding; electropolishing gives the best surface for acid and pharma service — no anodizing applies.
1.4537 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 weld corrosion resistance | ≤ 0.02 | 0.02 |
| Si | ≤ 0.7 | 0.35 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.01 | 0 |
| Cr | 24 – 26 | 25 |
| Nistabilises austenite, resists SCC | 24 – 27 | 25 |
| Mo | 4.7 – 5.7 | 5.2 |
| Cuboosts sulfuric/phosphoric acid resistance | 1 – 2 | 1.5 |
| Nraises PREN and yield strength | 0.17 – 0.25 | 0.2 |
| Fe | balance | — |
1.4537 HR-AT — frequently asked
What is 1.4537 HR-AT used for?
1.4537 HR-AT is typically used for sulfuric acid coolers, phosphoric acid production, seawater desalination and chemical reactor vessels. In short: pitting resistance above 904L; hot sulfuric acid grade; needs Ni-base weld filler.
What is the yield strength of 1.4537 HR-AT?
1.4537 HR-AT has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 55% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1.4537 HR-AT easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Very gummy and strongly work hardening — use rigid setups, positive-rake sharp carbide/coated inserts, heavy feed with low-to-moderate speed (≈30–60 m/min turning), high-pressure coolant, and never dwell in the cut.
Can 1.4537 HR-AT be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW/SMAW with over-alloyed Ni-base filler (ERNiCrMo-3/-4 or ERNiCrMo-13) to avoid Mo segregation; keep interpass ≤100–150 °C, no preheat, low heat input, back-purge with Ar (+N2) and pickle/passivate after welding.
What surface finishes work on 1.4537 HR-AT?
Pickle in HNO3-HF and passivate (ASTM A967) after hot work or welding; electropolishing gives the best surface for acid and pharma service — no anodizing applies.
Can 1.4537 HR-AT be formed, bent or molded?
Cold forms well but needs ≈50 % more force than 304 and generous springback allowance; hot work 1150–1200 °C followed by mandatory solution anneal 1100–1150 °C with rapid water quench.
What is the maximum service temperature of 1.4537 HR-AT?
1.4537 HR-AT 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 1.4537-AT and 1.4537-CD?
AT is the default condition — standard supply condition for plate, sheet, tube and forgings — maximum corrosion resistance and ductility. CD: bar stock for pump shafts, fasteners and valve stems needing higher yield strength and tight tolerance. Yield strength is 350 MPa in AT versus 560 MPa in CD.
Sources
- EN 10088-1/-2 Stainless steels — list of grades, technical delivery conditions for sheet/plate — CEN (2014)
- ASTM A240 / A480 (UNS N08935 superaustenitic plate, sheet and strip) — ASTM International (2022)
- UR™ B66 / Alloy 32 superaustenitic stainless steel data sheet — Industeel (ArcelorMittal) (2020)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
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.