Refractory Metal Zr 705-ANN (Annealed)
Heat-treated state · default condition
UNS R60705 · ASTM B550/B551 Grade 705
Standard stocked condition for plate, sheet, bar and pipe in chemical-process equipment; best ductility/weld-repair behaviour at full corrosion resistance.
Values for the ANN condition
Other Zr 705 tempers and conditions
Zr 705 is listed in 4 conditions; see the grade overview at Zr 705.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefaultThis page Annealed | Standard stocked condition for plate, sheet, bar and pipe in chemical-process equipment; best ductility/weld-repair behaviour at full corrosion resistance. | 450 | 620 | 20 | 200 HB | — |
Hot worked / as-forged | Heavy forgings, valve bodies and thick bar supplied hot worked where full annealing of the section is not practical. | 490 | 650 | 18 | 210 HB | 3.1 % IACS |
Cold worked and stress relieved | Choose for bar, wire, fasteners and thin tube where higher strength and better dimensional stability are needed and cold formability is not required. | 620 | 760 | 13 | 25 HRC | — |
Beta quenched and aged | Specialty high-strength condition for springs, shafts and pressure-tube-type parts; precipitation of β-Nb raises strength but lowers ductility and is not covered by the standard B550 mechanical table. | 760 | 900 | 10 | 32 HRC | 3 % IACS |
What is Zr 705-ANN?
Zr 705-ANN is Zr 705 heat treated to ANN — standard stocked condition for plate, sheet, bar and pipe in chemical-process equipment; best ductility/weld-repair behaviour at full corrosion resistance. Zr 705-ANN has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 69% of refractory metal grades. Elongation at break is 20% and the elastic modulus is 97 GPa (14.1 Msi). Zr 705-ANN has a density of 6.64 g/cm³ (0.24 lb/in³), lighter than 63% of refractory metal grades. It melts at 1,840°C (3,344 °F).
Limitations
- Low stiffness — 97 GPa (14.1 Msi), worse than 91% of refractory metal grades
- Low electrical conductivity — 3.1 % IACS, worse than 78% of refractory metal grades
- Poor heat conductor — 17.1 W/m·K (9.88 BTU/hr·ft·°F), worse than 76% of refractory metal grades
Zr 705-ANN properties
Typical room-temperature values for Zr 705-ANN; 13 are specific to this condition. Other listed values are Zr 705 reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical2
Zr 705-ANN has a density of 6.64 g/cm³ (0.24 lb/in³), lighter than 63% of refractory metal grades. It melts at 1,840°C (3,344 °F).
Mechanical16
Zr 705-ANN has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 69% of refractory metal grades. Elongation at break is 20% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
Zr 705-ANN is rated for continuous service to 400°C (752 °F). It conducts heat at 17.1 W/m·K (9.88 BTU/hr·ft·°F), worse than 76% of refractory metal grades. Thermal expansion is 6.3 µm/m·K (3.5 µin/in·°F).
Electrical3
Zr 705-ANN conducts electricity at 3.1 % IACS, worse than 78% 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 705-ANN takes about 1,400 MJ of energy and emits 85 kg of CO₂ — more than 67% of refractory metal grades. Typical recycled content is 25%.
Manufacturability8
Zr 705-ANN's machinability is fair (35/100, better than 81% of refractory metal grades); weldability good (65/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Zr 705-ANN
Is Zr 705 easy to machine?
Machine like austenitic stainless but slower: sharp uncoated carbide, positive rake, heavy rigid setups, generous chlorine-free flood coolant; fine chips are pyrophoric so keep them wet and collect separately.
Can Zr 705 be welded?
GTAW/EBW with high-purity argon or helium and full trailing/back purge (or chamber welding); target weld-zone hardness rise <30 HV and keep oxygen/nitrogen pickup minimal — no flux, no air exposure above ~300 °C.
Can Zr 705 be formed, bent or molded?
Cold formability is limited (bend radius ≥3–5t); warm forming at 200–400 °C and generous radii are preferred, and springback is high due to the low modulus.
What surface finishes work on Zr 705?
Pickle in HNO₃/HF to remove oxide and grinding smear before service; can be bead blasted or polished, and anodic coloring/oxide films are used for galling and ID marking.
Zr 705 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 |
|---|---|---|
| Nbcolumbium (niobium), principal alloying addition | 2 – 3 | 2.5 |
| Hfhafnium is not separated in industrial (non-nuclear) grades | ≤ 4.5 | 1 |
| Fe+Cr | ≤ 0.2 | 0.1 |
| O | ≤ 0.18 | 0.11 |
| C | ≤ 0.05 | 0.02 |
| N | ≤ 0.03 | 0.01 |
| H | ≤ 0.01 | 0 |
| Zr+Hfbalance, Zr+Hf min 95.5% per ASTM B550/B551 | ≥ 95.5 (balance) | — |
Zr 705-ANN — frequently asked
What is Zr 705-ANN used for?
Zr 705-ANN is typically used for high-strength process piping, pressure vessel components and fasteners in corrosive service. In short: strongest wrought zirconium; nb-alloyed corrosion grade; fastener-capable zirconium.
What is the yield strength of Zr 705-ANN?
Zr 705-ANN has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 69% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Zr 705-ANN easy to machine?
Not especially — machinability is rated fair (35/100, better than 81% of refractory metal grades). Machine like austenitic stainless but slower: sharp uncoated carbide, positive rake, heavy rigid setups, generous chlorine-free flood coolant; fine chips are pyrophoric so keep them wet and collect separately.
Can Zr 705-ANN be welded?
Yes — weldability is rated good (65/100). GTAW/EBW with high-purity argon or helium and full trailing/back purge (or chamber welding); target weld-zone hardness rise <30 HV and keep oxygen/nitrogen pickup minimal — no flux, no air exposure above ~300 °C.
What surface finishes work on Zr 705-ANN?
Pickle in HNO₃/HF to remove oxide and grinding smear before service; can be bead blasted or polished, and anodic coloring/oxide films are used for galling and ID marking.
Can Zr 705-ANN be formed, bent or molded?
Cold formability is limited (bend radius ≥3–5t); warm forming at 200–400 °C and generous radii are preferred, and springback is high due to the low modulus.
What is the maximum service temperature of Zr 705-ANN?
Zr 705-ANN 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 705-ANN and Zr 705-BQA?
ANN is the default condition — standard stocked condition for plate, sheet, bar and pipe in chemical-process equipment; best ductility/weld-repair behaviour at full corrosion resistance. BQA: specialty high-strength condition for springs, shafts and pressure-tube-type parts; precipitation of β-Nb raises strength but lowers ductility and is not covered by the standard B550 mechanical table. Yield strength is 450 MPa in ANN versus 760 MPa in BQA.
Sources
- ASTM B550/B550M Zirconium and Zirconium Alloy Bar and Wire — ASTM International (2018)
- ASTM B551/B551M Zirconium and Zirconium Alloy Strip, Sheet and Plate — ASTM International (2018)
- ASTM B523 / B658 Zirconium Alloy Tube and Pipe — ASTM International (2018)
- Zirconium Alloys 702/704/705 Technical Data — ATI Wah Chang (2016)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Zirconium) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (Zirconium) — 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.