Recrystallisation & hot strength
Metallurgical condition as supplied Required by the standard
| Form | Available condition |
|---|---|
| Strip | Hot-rolled; hot-rolled annealed; cold-rolled; cold-rolled annealed; cold-rolled annealed followed by a final light cold-rolled pass, generally on polished rolls |
| Sheet | Hot-rolled; hot-rolled annealed; cold-rolled annealed; cold-rolled annealed followed by a final light cold-rolled pass |
| Plate | Hot-rolled; hot-rolled annealed |
| Metallurgical condition (default) | Recrystallised annealed |
Strip, sheet and plate are supplied recrystallization annealed unless the purchase order specifies otherwise. The metallurgical condition defaults to recrystallised annealed.
The rolling and finish condition has several options and must be specified on the purchase order.
The two do not conflict: the metallurgical condition has a default, the rolling and finish condition does not.
⚠ The available conditions narrow with the form: strip has a plain cold-rolled (un-annealed) option that sheet does not, and plate has only hot-rolled and hot-rolled annealed. Ordering strip from experience with sheet, or the reverse, can ask for a condition that is not offered.
Protective annealing atmosphere Required by the standard
Not permitted — No protective annealing atmosphere is prescribed; hydrogen and nitrogen are instead determined on the finished product.
The ingot analysis may represent the finished product's composition, EXCEPT for hydrogen and nitrogen, which must be determined on the finished product. Zirconium picks up hydrogen during annealing and embrittles badly, which is why hydrogen is checked on the finished product, much as for niobium.
⚠ Elements outside the listed chemistry are not analysed unless specified — they are assumed to arise only from unregulated scrap additions to the melt. A trace-element scan has to be agreed in the written purchase order.
Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements3 elements | |||
| Zr+Hf | Zirconium + hafnium | ≥ 95.5% | |
| Nb | Niobium | 2 – 3% | |
| Zr | Zirconium | Bal. | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual6 elements | |||
| Hf | Hafnium | ≤ 4.5% | |
| Fe+Cr | Iron + chromium | ≤ 0.2% | |
| H | Hydrogen | ≤ 0.005% | |
| N | Nitrogen | ≤ 0.025% | |
| C | Carbon | ≤ 0.05% | |
| O | Oxygen | ≤ 0.18% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % |
|---|---|---|---|---|
| Forgings | As supplied to the standard | ≥ 485 (70 ksi) | ≥ 380 (55 ksi) | ≥ 16 |
Where this grade is recommended
Matched in 1 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Nuclear fuel cladding & grids | Power & Nuclear | 350 – 400 °C | 1 / 4 | 90 |
Designations & equivalents
| EN designation | Zr-2.5Nb |
| Trade name(s) | Zr705 / Zircadyne 705 |
| ASTM / AISI | B493 / B550 / B551 / B653 / B658 |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
5 specifications. Name the standard and its edition on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is Zirconium 705 (Zr-Nb) · UNS R60705?
Zirconium 705 (Zr-Nb) · UNS R60705 — Zirconium. Higher-strength zirconium for pressure equipment
What is the maximum service temperature of R60705?
Typically about 350 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of R60705?
The specified minimum tensile strength is 485 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover R60705?
ASTM B493/B493M, ASTM B550/B550M, ASTM B551/B551M, ASTM B653/B653M, ASTM B658/B658M
Where is R60705 typically used?
Nuclear fuel cladding & grids (Power & Nuclear)
In which forms is R60705 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
Or email us: info@kochlin.com