Refractory Metal Zircaloy-4
UNS R60804 · ASTM B350/B811
Zircaloy-4 (UNS R60804, ASTM B350/B811) is a nickel-free Zr-Sn-Fe-Cr alloy and the standard material for PWR fuel cladding and guide tubes.
Reference datasheet — Zircaloy-4 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the RXA condition
Zircaloy-4 tempers and conditions
Zircaloy-4 is supplied in 5 conditions, soft to hard. RXA is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
RXADefault Fully recrystallization annealed | Standard stocked condition for plate, sheet, bar and structural components; maximum ductility and creep-friendly isotropy. | 330 | 480 | 28 | 89 HRB | — |
Β-Q | Used for guide tube/end-plug stock and nodular-corrosion resistance; fine Widmanstätten structure with uniformly dispersed Zr(Fe,Cr)2 precipitates. | 380 | 520 | 18 | 13 HRC | 2.4 % IACS |
Partially recrystallized annealed | Intermediate temper for cladding and spacer strip where a balance of strength, creep and corrosion behaviour is wanted. | 430 | 560 | 20 | 14 HRC | 2.5 % IACS |
CWSR / SRA | Standard condition for PWR fuel cladding and guide tubes (ASTM B811); highest strength and best creep-collapse resistance. | 540 | 640 | 14 | 97 HRB | — |
Cold worked | Intermediate mill condition or springy strip/wire use; highest strength but low ductility and high residual stress. | 670 | 740 | 9 | 24 HRC | 2.4 % IACS |
What is Zircaloy-4?
Zircaloy-4 (UNS R60804, ASTM B350/B811) is a nickel-free Zr-Sn-Fe-Cr alloy and the standard material for PWR fuel cladding and guide tubes. Removing nickel lowers in-reactor hydrogen pickup relative to Zircaloy-2 while keeping the low neutron-absorption cross-section; it is supplied as cold-worked stress-relieved, recrystallised and beta-quenched tube, strip, sheet and bar. Typical values are 330 MPa yield, 480 MPa tensile, 28% elongation and 89 HRB, with service around 400 °C. Machinability is low (score 30), chips are pyrophoric and welding needs full inert-gas or vacuum shielding; Zr-2.5Nb is the choice when higher strength and creep resistance are required. Zircaloy-4 has a density of 6.56 g/cm³ (0.237 lb/in³), lighter than 71% of refractory metal grades. It melts at 1,760°C (3,200 °F). Zircaloy-4 has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 50% of refractory metal grades. Elongation at break is 28% and the elastic modulus is 99 GPa (14.4 Msi).
What is Zircaloy-4 used for?
- PWR fuel cladding
- Guide tubes
- Fuel assembly spacers
Advantages
- Tough — resists crack growth — 70 MPa·√m (63.7 ksi·√in), better than 84% of refractory metal grades
- Ductile — tolerates forming and impact — 28%, better than 80% of refractory metal grades
- Forms and bends easily — 70/100, better than 75% of refractory metal grades
Limitations
- Poor heat conductor — 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 95% of refractory metal grades
- Low electrical conductivity — 2.5 % IACS, worse than 86% of refractory metal grades
- Low stiffness — 99 GPa (14.4 Msi), worse than 79% of refractory metal grades
Zircaloy-4 properties
Typical room-temperature values for Zircaloy-4-RXA; bars are the position among refractory metal grades.
Physical3
Zircaloy-4 has a density of 6.56 g/cm³ (0.237 lb/in³), lighter than 71% of refractory metal grades. It melts at 1,760°C (3,200 °F).
Mechanical15
Zircaloy-4 has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 50% of refractory metal grades. Elongation at break is 28% and the elastic modulus is 99 GPa (14.4 Msi).
Thermal6
Zircaloy-4 is rated for continuous service to 400°C (752 °F). It conducts heat at 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 95% of refractory metal grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical3
Zircaloy-4 conducts electricity at 2.5 % IACS, worse than 86% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 64% of refractory metal grades.
Sustainability4
Producing a kilogram of Zircaloy-4 takes about 1,400 MJ of energy and emits 90 kg of CO₂ — more than 67% of refractory metal grades. Typical recycled content is 10%.
Manufacturability8
Zircaloy-4's machinability is poor (30/100, better than 54% of refractory metal grades); weldability very good (72/100); formability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the refractory metal family
Yield strength against density for every refractory metal grade FabDigit runs. Zircaloy-4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Zircaloy-4
Is Zircaloy-4 easy to machine?
Machine like CP-titanium: sharp, positive-rake carbide, slow speed, heavy flood coolant, no dwelling — chips are pyrophoric, so collect wet and never dry-grind.
Can Zircaloy-4 be welded?
GTAW, plasma or EB weld only under high-purity argon/helium chamber or full trailing plus back purge; any O/N/H pickup embrittles the weld, and no filler other than matching Zr is acceptable.
Can Zircaloy-4 be formed, bent or molded?
Cold form annealed sheet with generous radii (≥2t) allowing for strong crystallographic texture and springback; hot work 700–800 °C, and tube reduce by cold pilgering with intermediate 550–600 °C vacuum anneals.
Zircaloy-4 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 |
|---|---|---|
| Snsolid-solution strengthener | 1.2 – 1.7 | 1.45 |
| FeFe+Cr must be 0.28–0.37 | 0.18 – 0.24 | 0.21 |
| Crforms Zr(Fe,Cr)2 precipitates | 0.07 – 0.13 | 0.1 |
| Ospecified/ordered range; main strengthener | 0.09 – 0.16 | 0.12 |
| Nideliberately restricted to limit hydrogen pickup | ≤ 0.01 | |
| Hfnuclear-grade limit (neutron absorber) | ≤ 0.01 | |
| C | ≤ 0.03 | |
| N | ≤ 0.01 | |
| Si | ≤ 0.01 | |
| Al | ≤ 0.01 | |
| B | ≤ 5×10⁻⁵ | |
| Cd | ≤ 5×10⁻⁵ | |
| Zrbalance Zr (+ residual Hf within limit) | balance |
What surface finishes work on Zircaloy-4?
Pickle in HNO3/HF then rinse and passivate/autoclave to grow a protective black ZrO2 film; avoid iron contamination from steel tooling, and use dedicated wire brushes and abrasives.
Equivalent designations
Standards and trade names that resolve to Refractory Metal Zircaloy-4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R60804
- ASTM
- B350/B811
How much does Zircaloy-4 cost?
Zircaloy-4 is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Zircaloy-4 — frequently asked
What is Zircaloy-4 used for?
Zircaloy-4 is typically used for PWR fuel cladding, guide tubes and fuel assembly spacers. In short: standard PWR cladding alloy; lower hydrogen pickup; nickel-free Zircaloy-2.
What is the yield strength of Zircaloy-4?
Zircaloy-4 has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 50% of refractory metal grades. Strength varies by condition: see the 5 listed tempers.
Is Zircaloy-4 easy to machine?
Not especially — machinability is rated poor (30/100, better than 54% of refractory metal grades). Machine like CP-titanium: sharp, positive-rake carbide, slow speed, heavy flood coolant, no dwelling — chips are pyrophoric, so collect wet and never dry-grind.
Can Zircaloy-4 be welded?
Yes — weldability is rated very good (72/100). GTAW, plasma or EB weld only under high-purity argon/helium chamber or full trailing plus back purge; any O/N/H pickup embrittles the weld, and no filler other than matching Zr is acceptable.
What surface finishes work on Zircaloy-4?
Pickle in HNO3/HF then rinse and passivate/autoclave to grow a protective black ZrO2 film; avoid iron contamination from steel tooling, and use dedicated wire brushes and abrasives.
Can Zircaloy-4 be formed, bent or molded?
Cold form annealed sheet with generous radii (≥2t) allowing for strong crystallographic texture and springback; hot work 700–800 °C, and tube reduce by cold pilgering with intermediate 550–600 °C vacuum anneals.
What is the maximum service temperature of Zircaloy-4?
Zircaloy-4 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 Zircaloy-4-RXA and Zircaloy-4-CW?
RXA is the default condition — standard stocked condition for plate, sheet, bar and structural components; maximum ductility and creep-friendly isotropy. CW: intermediate mill condition or springy strip/wire use; highest strength but low ductility and high residual stress. Yield strength is 330 MPa in RXA versus 670 MPa in CW.
How much does Zircaloy-4 cost?
Zircaloy-4 is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B350/B350M — Zirconium and Zirconium Alloy Ingots for Nuclear Application — ASTM International (2022)
- ASTM B351 / B352 / B353 — Zr alloy bar/wire, sheet-strip-plate, and tubing for nuclear application — ASTM International (2022)
- ASTM B811 — Wrought Zirconium Alloy Seamless Tubes for Nuclear Reactor Fuel Cladding — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Zirconium and Hafnium) — ASM International (1990)
- MATPRO / NUREG-CR Zircaloy thermophysical and mechanical property correlations — US NRC / INL (2003)
- Zircaloy-4 alloy data sheet — ATI Wah Chang (2018)
- IAEA TECDOC — Waterside corrosion and properties of zirconium alloy fuel cladding — IAEA (1998)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.