Refractory Metal Zr 705
UNS R60705 · ASTM B550/B551 Grade 705
Zr 705 is the niobium-alloyed (about 2–3% Nb) wrought zirconium of ASTM B550/B551 Grade 705 (UNS R60705), supplied annealed, cold-worked/stress-relieved, hot-worked or beta-quenched and aged.
Reference datasheet — Zr 705 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 ANN condition
Zr 705 tempers and conditions
Zr 705 is supplied in 4 conditions, soft to hard. ANN 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 |
|---|---|---|---|---|---|---|
ANNDefault 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?
Zr 705 is the niobium-alloyed (about 2–3% Nb) wrought zirconium of ASTM B550/B551 Grade 705 (UNS R60705), supplied annealed, cold-worked/stress-relieved, hot-worked or beta-quenched and aged. It is the strongest commercial wrought zirconium — 450 MPa yield, 620 MPa tensile, 20% elongation, 200 HB (95 HRB) — with a corrosion score of 92, so it is specified for pressure parts and fasteners in hot acids up to about 400 °C. Cold formability is limited (score 40) and weldability lower than the pure grades (65); Zr 702 or Zr 706 suit work where forming or welding dominates. Zr 705 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). Zr 705 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).
What is Zr 705 used for?
- High-strength process piping
- Pressure vessel components
- Fasteners in corrosive service
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 properties
Typical room-temperature values for Zr 705-ANN; bars are the position among refractory metal grades.
Physical2
Zr 705 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 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 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 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 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'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. 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 705 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Zr 705
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.
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) |
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.
Equivalent designations
Standards and trade names that resolve to Refractory Metal Zr 705 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R60705
- ASTM
- B550/B551 Grade 705
How much does Zr 705 cost?
Zr 705 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 705 — frequently asked
What is Zr 705 used for?
Zr 705 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?
Zr 705 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 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 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?
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 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?
Zr 705 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.
How much does Zr 705 cost?
Zr 705 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 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; 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.