Refractory Metal Zr 705 CWSR
Heat-treated state
UNS R60705 · ASTM B550/B551 Grade 705
CWSR = 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.
Values for the CWSR 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 |
|---|---|---|---|---|---|---|
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 |
CWSRThis page 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 CWSR?
Zr 705 CWSR is Zr 705 heat treated to CWSR — choose for bar, wire, fasteners and thin tube where higher strength and better dimensional stability are needed and cold formability is not required. Zr 705 CWSR has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 84% of refractory metal grades. Elongation at break is 13% and the elastic modulus is 97 GPa (14.1 Msi). Zr 705 CWSR 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). ANN is the default condition FabDigit quotes; CWSR is available on request or by drawing note.
Advantages
- High strength — 620 MPa (89.9 ksi), better than 84% of refractory metal grades
Limitations
- Low stiffness — 97 GPa (14.1 Msi), worse than 91% of refractory metal grades
- Limited service temperature — 350°C (662 °F), worse than 89% 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 CWSR properties
Typical room-temperature values for Zr 705 CWSR; 10 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 CWSR 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 CWSR has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 84% of refractory metal grades. Elongation at break is 13% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
Zr 705 CWSR is rated for continuous service to 350°C (662 °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 CWSR 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 CWSR 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 CWSR's machinability is fair (38/100, better than 90% of refractory metal grades); weldability good (55/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Zr 705 CWSR
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 CWSR — frequently asked
What is Zr 705 CWSR used for?
Zr 705 CWSR 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 CWSR?
Zr 705 CWSR has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 84% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Zr 705 CWSR easy to machine?
Not especially — machinability is rated fair (38/100, better than 90% 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 CWSR be welded?
Yes — weldability is rated good (55/100). 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 CWSR?
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 CWSR 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 CWSR?
Zr 705 CWSR is rated for continuous use to about 350°C (662 °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.