Zr705 Zirconium Alloy Round Bar
- High-strength zirconium-niobium alloy (Zr-2.5Nb), UNS R60705
- Tensile strength ≥552 MPa — approximately twice that of Zr702, with yield strength ≥379 MPa
- Excellent corrosion resistance in superheated water, steam, and aggressive chemical media
- Superior to Zr702 in high-temperature and high-pressure applications
- Forms a stable, dense, self-healing protective oxide layer
- Excellent ductility even at cryogenic temperatures
- Good formability and weldability
Description Of Zr705 Zirconium Alloy Round Bar
Zr705 Zirconium Alloy Round Bar is a high-performance zirconium-niobium alloy (Zr-2.5Nb) designated as UNS R60705, manufactured through vacuum arc remelting, forging, and precision machining. It is alloyed with niobium to increase its strength and improve its formability compared to commercially pure zirconium. Zr705 offers approximately twice the tensile strength of Zr702, making it the material of choice for high-pressure and high-temperature applications where the strength of pure zirconium is insufficient.
Zirconium 705 is composed of 95.5% minimum zirconium and hafnium (with a maximum hafnium content of 4.5%), alloyed with 2.0% to 3.0% niobium. It forms a stable, dense, self-healing protective oxide layer that provides exceptional corrosion resistance. This protective oxide layer can be further enhanced through a heat treating process, creating a robust barrier that serves as an excellent bearing surface and imparts impressive erosion resistance in high-velocity systems.
Zr705 zirconium alloy round bar is widely used in nuclear reactor structural components, chemical processing equipment, heat exchangers, and other high-performance engineering applications. It exhibits good ductility even at cryogenic temperatures and strength comparable with other common engineering alloys.
The material is compliant with ASTM B550/B550M, the standard specification for zirconium and zirconium alloy bar and wire, which covers Grade R60705 (zirconium-niobium). Custom diameters, lengths, and surface finishes are available upon request.
Applications Of Zr705 Zirconium Alloy Round Bar
Nuclear Industry: Fuel rod cladding, pressure vessels, heat exchangers, and reactor structural components. Zr705's low neutron absorption cross-section and excellent corrosion resistance in high-temperature water and steam make it ideal for nuclear applications.
Chemical Processing: Heat exchangers, condensers, reaction vessels, columns, and piping systems handling strong acids and corrosive media. Zr705 offers superior corrosion resistance compared to Zr702 and is used where higher strength is required.
Hydrogen Generation: Heat exchangers and structural components for nuclear hydrogen generation using thermochemical processes that involve the decomposition of hydroiodic acid at temperatures up to 400°C.
Petrochemical Industry: Pumps, valves, and reactor linings exposed to strong acids and corrosive environments.
Medical Gas Pipeline Systems: Components for medical gas delivery systems requiring high purity and corrosion resistance.
Oil and Gas: Downhole tools, wellhead equipment, and pipeline systems where corrosion resistance and high strength are required.
Aerospace and Marine: Structural components and seawater-cooled equipment requiring lightweight, high-strength, and corrosion-resistant materials.
Specifications Of Zr705 Zirconium Alloy Round Bar
| Parameter | Specification |
|---|---|
| Material | Zirconium-niobium alloy (Zr-2.5Nb) |
| UNS Designation | R60705 |
| Zirconium + Hafnium, min | 95.5% |
| Hafnium, max | 4.5% |
| Niobium (Columbium) | 2.0 – 3.0% |
| Iron + Chromium, max | 0.20% |
| Hydrogen, max | 0.005% |
| Nitrogen, max | 0.025% |
| Carbon, max | 0.05% |
| Oxygen, max | 0.18% |
| Density | 6.64 g/cm³ |
| Melting Point | 1840°C |
| Tensile Strength | ≥552 MPa |
| Yield Strength (0.2% offset) | ≥379 MPa |
| Elongation | ≥16% |
| Hardness (Rockwell B) | 80 |
| Diameter Range | 6 – 150 mm (customizable) |
| Length | Customizable |
| Surface Finish | Pickled, machined, polished |