Refractory Metal Zr 704-AW (As-welded deposit)
Heat-treated state
UNS R60704 · ASTM B550/B551 Grade 704
Reference condition for design of welded Zr 704 vessels; strength close to base metal but ductility is reduced if shielding is imperfect.
Values for the AW condition
Other Zr 704 tempers and conditions
Zr 704 is listed in 4 conditions; see the grade overview at Zr 704.
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 | — |
AWThis page 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-AW?
Zr 704-AW is Zr 704 heat treated to AW — reference condition for design of welded Zr 704 vessels; strength close to base metal but ductility is reduced if shielding is imperfect. Zr 704-AW has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 60% of refractory metal grades. Elongation at break is 14% and the elastic modulus is 99 GPa (14.4 Msi). Zr 704-AW 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). Annealed is the default condition FabDigit quotes; AW is available on request or by drawing note.
Advantages
- Readily welded — 75/100, better than 81% 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-AW properties
Typical room-temperature values for Zr 704-AW; 22 are specific to this condition. Other listed values are Zr 704 reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
Zr 704-AW 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-AW has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 60% of refractory metal grades. Elongation at break is 14% and the elastic modulus is 99 GPa (14.4 Msi).
Thermal6
Zr 704-AW 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-AW conducts electricity at 3.4 % IACS, worse than 72% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 64% of refractory metal grades.
Sustainability4
Producing a kilogram of Zr 704-AW 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-AW's machinability is poor (28/100, worse than 58% of refractory metal grades); weldability very good (75/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Zr 704-AW
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.
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.
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) | — |
Zr 704-AW — frequently asked
What is Zr 704-AW used for?
Zr 704-AW 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-AW?
Zr 704-AW has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 60% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Zr 704-AW easy to machine?
Not especially — machinability is rated poor (28/100, worse than 58% 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-AW be welded?
Yes — weldability is rated very good (75/100). 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-AW?
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-AW 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-AW?
Zr 704-AW 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.