Refractory Metal Zr 704
UNS R60704 · ASTM B550/B551 Grade 704
Zr 704 is a tin-alloyed wrought zirconium ordered to ASTM B550/B551 Grade 704 (UNS R60704) in annealed, cold-worked/stress-relieved, hot-worked and as-welded conditions.
Reference datasheet — Zr 704 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 Annealed condition
Zr 704 tempers and conditions
Zr 704 is supplied in 4 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault recrystallization annealed (mill standard for B550/B551/B523) | Default stocked condition for plate, sheet, bar and tube; best ductility and formability with guaranteed ASTM minimums. | 300 | 470 | 22 | 88 HRB | — |
As-welded deposit | Reference condition for design of welded Zr 704 vessels; strength close to base metal but ductility is reduced if shielding is imperfect. | 300 | 460 | 14 | 192 HB | 3.4 % IACS |
Hot Worked / As-Forged | Pick for heavy forged valve bodies and flanges where section size makes full annealing impractical. | 320 | 480 | 18 | 185 HB | 3.4 % IACS |
Cold Worked and Stress Relieved | Choose for tubing, rod and fasteners needing higher strength and better dimensional stability than fully annealed material. | 480 | 600 | 14 | 20 HRC | 3.3 % IACS |
What is Zr 704?
Zr 704 is a tin-alloyed wrought zirconium ordered to ASTM B550/B551 Grade 704 (UNS R60704) in annealed, cold-worked/stress-relieved, hot-worked and as-welded conditions. The Sn addition raises strength over commercially pure Zr 702 — 300 MPa yield, 470 MPa tensile, 22% elongation, 88 HRB — while keeping the same protective oxide behaviour in acids, so it is used for piping, tubing and vessel parts rated to about 400 °C. Formability is moderate (score 55) and machinability low (30); Zr 705 is the choice when higher strength is needed. Zr 704 has a density of 6.57 g/cm³ (0.237 lb/in³), lighter than 67% of refractory metal grades. It melts at 1,840°C (3,344 °F). Zr 704 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 60% of refractory metal grades. Elongation at break is 22% and the elastic modulus is 99 GPa (14.4 Msi).
What is Zr 704 used for?
- Process piping
- Heat exchanger tubing
- Chemical vessel components
Advantages
- Readily welded — 80/100, better than 92% of refractory metal grades
Limitations
- Poor heat conductor — 14.6 W/m·K (8.44 BTU/hr·ft·°F), worse than 84% of refractory metal grades
- Low stiffness — 99 GPa (14.4 Msi), worse than 79% of refractory metal grades
- High embodied carbon — 95 kg CO₂/kg, worse than 75% of refractory metal grades
Zr 704 properties
Typical room-temperature values for Zr 704-Annealed; bars are the position among refractory metal grades.
Physical3
Zr 704 has a density of 6.57 g/cm³ (0.237 lb/in³), lighter than 67% of refractory metal grades. It melts at 1,840°C (3,344 °F).
Mechanical16
Zr 704 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 60% of refractory metal grades. Elongation at break is 22% and the elastic modulus is 99 GPa (14.4 Msi).
Thermal6
Zr 704 is rated for continuous service to 400°C (752 °F). It conducts heat at 14.6 W/m·K (8.44 BTU/hr·ft·°F), worse than 84% of refractory metal grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical3
Zr 704 conducts electricity at 3.4 % IACS, worse than 72% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 86% of refractory metal grades.
Sustainability4
Producing a kilogram of Zr 704 takes about 1,400 MJ of energy and emits 95 kg of CO₂ — more than 67% of refractory metal grades. Typical recycled content is 20%.
Manufacturability8
Zr 704's machinability is poor (30/100, better than 54% of refractory metal grades); weldability very good (80/100); formability good (55/100).
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. Zr 704 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Zr 704
Is Zr 704 easy to machine?
Use slow speeds, heavy positive-rake sharp carbide tooling and flood coolant; chips are pyrophoric — keep them wet and collect separately.
Can Zr 704 be welded?
GTAW/EBW with high-purity argon, trailing shield and back purge (<20 ppm O2/N2); a bright silver weld is acceptable, white or grey indicates contamination.
Can Zr 704 be formed, bent or molded?
Cold-form on generous radii (≥3–5t) with slow rams; warm forming at 200–400 °C improves bendability, and tools should be lubricated to avoid galling.
Zr 704 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 |
|---|---|---|
| Sn | 1 – 2 | 1.5 |
| Fe+Crcombined iron plus chromium | 0.2 – 0.4 | 0.3 |
| Hfhafnium is a natural companion of zirconium | ≤ 4.5 | 2 |
| O | ≤ 0.18 | 0.12 |
| C | ≤ 0.05 | 0.02 |
| N | ≤ 0.03 | 0.01 |
| H | ≤ 0.01 | 0 |
| Zr+Hfbalance zirconium plus hafnium | ≥ 97.5 (balance) |
What surface finishes work on Zr 704?
Pickle in HNO3–HF to remove oxide and hydride skin after hot work; can be electropolished or anodized for colour, but avoid iron contamination from grinding media.
Equivalent designations
Standards and trade names that resolve to Refractory Metal Zr 704 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R60704
- ASTM
- B550/B551 Grade 704
How much does Zr 704 cost?
Zr 704 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.
Zr 704 — frequently asked
What is Zr 704 used for?
Zr 704 is typically used for process piping, heat exchanger tubing and chemical vessel components. In short: sn-strengthened zirconium; stronger than Zr 702; 400 °C acid-service grade.
What is the yield strength of Zr 704?
Zr 704 has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 60% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Zr 704 easy to machine?
Not especially — machinability is rated poor (30/100, better than 54% of refractory metal grades). Use slow speeds, heavy positive-rake sharp carbide tooling and flood coolant; chips are pyrophoric — keep them wet and collect separately.
Can Zr 704 be welded?
Yes — weldability is rated very good (80/100). GTAW/EBW with high-purity argon, trailing shield and back purge (<20 ppm O2/N2); a bright silver weld is acceptable, white or grey indicates contamination.
What surface finishes work on Zr 704?
Pickle in HNO3–HF to remove oxide and hydride skin after hot work; can be electropolished or anodized for colour, but avoid iron contamination from grinding media.
Can Zr 704 be formed, bent or molded?
Cold-form on generous radii (≥3–5t) with slow rams; warm forming at 200–400 °C improves bendability, and tools should be lubricated to avoid galling.
What is the maximum service temperature of Zr 704?
Zr 704 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 Zr 704 Annealed and Zr 704 CW-SR?
Annealed is the default condition — default stocked condition for plate, sheet, bar and tube; best ductility and formability with guaranteed ASTM minimums. CW-SR: choose for tubing, rod and fasteners needing higher strength and better dimensional stability than fully annealed material. Yield strength is 300 MPa in Annealed versus 480 MPa in CW-SR.
How much does Zr 704 cost?
Zr 704 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 B551/B551M — Zirconium and Zirconium Alloy Strip, Sheet and Plate — ASTM International (2019)
- ASTM B550/B550M — Zirconium and Zirconium Alloy Bar and Wire — ASTM International (2020)
- ASTM B523 / B658 — Zirconium Alloy Seamless and Welded Tube and Pipe — ASTM International (2022)
- Zirconium Alloys 702/704/705 technical data — ATI (Wah Chang) (2020)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.