Stainless Steel Alloy 611 CW-1/4H
Supply condition
UNS S30601
CW-1/4H = 1/4 Hard
Use only where extra stiffness/strength is needed and the part will not see high-stress acid service (SCC and film-forming behaviour favour the annealed state).
Values for the CW-1/4H condition
Other Alloy 611 tempers and conditions
Alloy 611 is listed in 4 conditions; see the grade overview at Alloy 611.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed and pickled (plate, sheet, tube, pipe) | Standard supply condition for all corrosion service — maximum ductility and a fully solutionized, film-forming surface. | 330 | 650 | 45 | 190 HB | — |
As-welded deposit | Condition of welded pipe/tube seams and site welds; expect slightly lower ductility and use over-alloyed or matching high-Si filler plus post-weld pickling for full acid resistance. | 350 | 640 | 30 | 200 HB | 1.8 % IACS |
Cold drawn | Bar/wire form for fasteners, spray nozzles and machined acid-plant fittings; anneal after heavy drawing if full corrosion performance is required. | 560 | 800 | 25 | 24 HRC | 1.8 % IACS |
CW-1/4HThis page 1/4 Hard | Use only where extra stiffness/strength is needed and the part will not see high-stress acid service (SCC and film-forming behaviour favour the annealed state). | 600 | 860 | 20 | 25 HRC | 1.8 % IACS |
What is Alloy 611 CW-1/4H?
Alloy 611 CW-1/4H is Alloy 611 supplied in the CW-1/4H condition — use only where extra stiffness/strength is needed and the part will not see high-stress acid service (SCC and film-forming behaviour favour the annealed state). Alloy 611 CW-1/4H has a yield strength of 600 MPa (87 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 193 GPa (28 Msi). Alloy 611 CW-1/4H has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,350°C (2,462 °F). Annealed is the default condition FabDigit quotes; CW-1/4H is available on request or by drawing note.
Advantages
- High strength — 600 MPa (87 ksi), better than 86% of stainless steel grades
Limitations
- Poor heat conductor — 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades
- High embodied carbon — 6 kg CO₂/kg, worse than 88% of stainless steel grades
- Limited ductility — 20%, worse than 79% of stainless steel grades
Alloy 611 CW-1/4H properties
Typical room-temperature values for Alloy 611 CW-1/4H; 24 are specific to this condition. Other listed values are Alloy 611 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
Alloy 611 CW-1/4H has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Mechanical13
Alloy 611 CW-1/4H has a yield strength of 600 MPa (87 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 193 GPa (28 Msi).
Thermal5
Alloy 611 CW-1/4H is rated for continuous service to 550°C (1,022 °F). It conducts heat at 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical2
Alloy 611 CW-1/4H has an electrical resistivity of 9.7×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 68% of stainless steel grades.
Sustainability4
Producing a kilogram of Alloy 611 CW-1/4H takes about 62 MJ of energy and emits 6 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
Alloy 611 CW-1/4H's machinability is poor (27/100, worse than 83% of stainless steel grades); weldability good (55/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Alloy 611 CW-1/4H
Is Alloy 611 easy to machine?
Treat as a tough, abrasive austenitic: rigid setups, sharp coated carbide, positive rake, 20–35 % lower speed than 304, heavy flood coolant, avoid dwell to prevent work hardening.
Can Alloy 611 be welded?
GTAW/GMAW/SAW with matching high-Si or over-alloyed austenitic filler, low heat input, no preheat, interpass below ~150 °C; keep dilution low and pickle/passivate the weld zone before acid service.
Can Alloy 611 be formed, bent or molded?
Cold forms like a high-work-hardening austenitic — allow generous bend radii, extra springback and intermediate annealing (1050–1120 °C, rapid cool) for severe drawing; hot work 900–1150 °C.
What surface finishes work on Alloy 611?
Pickle in nitric/HF or nitric-based passivating bath to remove the silica-rich scale after welding or annealing; mechanical polishing works well, no anodizing or plating normally used.
Alloy 611 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 to avoid sensitization | ≤ 0.02 | 0.01 |
| Sikey element for the sulfuric-acid passive film | 5 – 5.6 | 5.3 |
| Mn | 0.4 – 1 | 0.6 |
| P | ≤ 0.03 | — |
| S | ≤ 0.01 | — |
| Cr | 17 – 18 | 17.5 |
| Nihigh Ni stabilizes austenite against the ferritizing effect of Si | 17 – 18 | 17.5 |
| Moresidual only — limits chloride pitting resistance | ≤ 0.2 | 0.1 |
| Cu | ≤ 0.35 | — |
| Fe | balance | — |
Alloy 611 CW-1/4H — frequently asked
What is Alloy 611 CW-1/4H used for?
Alloy 611 CW-1/4H is typically used for high-temperature furnace components, petrochemical process tubing, furnace retorts in sulfidising atmospheres, radiant tubes, carburizing furnace fixtures and reformer and heater hardware. In short: sulfidation-resistant 310 variant; molybdenum-modified heat-resistant grade; tougher to machine than 304.
What is the yield strength of Alloy 611 CW-1/4H?
Alloy 611 CW-1/4H has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 86% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is Alloy 611 CW-1/4H easy to machine?
Not especially — machinability is rated poor (27/100, worse than 83% of stainless steel grades). Treat as a tough, abrasive austenitic: rigid setups, sharp coated carbide, positive rake, 20–35 % lower speed than 304, heavy flood coolant, avoid dwell to prevent work hardening.
Can Alloy 611 CW-1/4H be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW/SAW with matching high-Si or over-alloyed austenitic filler, low heat input, no preheat, interpass below ~150 °C; keep dilution low and pickle/passivate the weld zone before acid service.
What surface finishes work on Alloy 611 CW-1/4H?
Pickle in nitric/HF or nitric-based passivating bath to remove the silica-rich scale after welding or annealing; mechanical polishing works well, no anodizing or plating normally used.
Can Alloy 611 CW-1/4H be formed, bent or molded?
Cold forms like a high-work-hardening austenitic — allow generous bend radii, extra springback and intermediate annealing (1050–1120 °C, rapid cool) for severe drawing; hot work 900–1150 °C.
What is the maximum service temperature of Alloy 611 CW-1/4H?
Alloy 611 CW-1/4H 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 Alloy 611 Annealed and Alloy 611-CD?
Annealed is the default condition — standard supply condition for all corrosion service — maximum ductility and a fully solutionized, film-forming surface. CD: bar/wire form for fasteners, spray nozzles and machined acid-plant fittings; anneal after heavy drawing if full corrosion performance is required. Yield strength is 330 MPa in Annealed versus 560 MPa in CD.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASTM A249/A269 — Welded and Seamless Austenitic Stainless Steel Tubing — ASTM International (2022)
- SAE/ASTM DS-56 (Metals & Alloys in the Unified Numbering System) — UNS S30601 — SAE International / ASTM (2017)
- High-silicon austenitic stainless steel for concentrated sulfuric acid (S30601 grade datasheet) — Sandvik Materials Technology / Alleima (2022)
- ASM Handbook Vol.13B — Corrosion: Materials (sulfuric acid service) — ASM International (2005)
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.