Grade 702 (Commercially Pure Zirconium) Technical Data Sheet
Alloy Overview
Grade 702 is a commercially pure zirconium grade with a minimum zirconium content of 99.2% (including a maximum of 4.5% hafnium). It contains controlled levels of iron (Fe), chromium (Cr), and oxygen (O), retaining zirconium’s inherent corrosion resistance while offering balanced mechanical properties. This grade is valued for its formability and reliability in aggressive environments.
Chemical Composition (Weight %)
Component
Content Range
Zr (Zr + Hf)
Min 99.2 (balance)
Fe + Cr
0.2
Hf
Max 4.5
O
0.16
Physical Properties
Property
Metric
English
Density
6.5 g/cc
0.235 lb/in³
Mechanical Properties
Property
Metric
English
Notes
Hardness (Rockwell A)
49
49
Estimated from Vickers
Hardness (Rockwell B)
78
78
Estimated from Vickers
Hardness (Vickers)
150
150
Annealed sample
Tensile Strength (Ultimate)
Min 379 MPa
Min 55,000 psi
Tensile Strength (Yield, 0.2%)
Min 207 MPa
Min 30,000 psi
0.2% offset
Elongation at Break
16%
16%
Measured in 50 mm
Modulus of Elasticity
99.3 GPa
14,400 ksi
Poisson’s Ratio
0.35
0.35
Shear Modulus
36.2 GPa
5,250 ksi
Fatigue Strength (Notched)
125 MPa
18,100 psi
5×10⁵ cycles
Fatigue Strength (Unnotched)
145 MPa
21,000 psi
3×10⁷ cycles
Fatigue Strength (Unnotched)
175 MPa
25,400 psi
5×10³ cycles
Fatigue Strength (Notched)
60 MPa
8,700 psi
3×10⁷ cycles
Electrical & Magnetic Properties
Property
Metric
English
Notes
Electrical Resistivity
3.97e-005 ohm-cm
3.97e-005 ohm-cm
Temp coefficient: 0.0044/°C at 20°C
Magnetic Susceptibility
1.34e-006 cgs/g
1.34e-006 cgs/g
Pure Zr
Critical Magnetic Field Strength
47 oersted
47 oersted
Pure Zr
Critical Superconducting Temperature
0.595 – 0.625 K
0.595 – 0.625 K
Pure Zr
Thermal Properties
Property
Metric
English
Notes
Heat of Fusion
250 J/g
108 BTU/lb
Linear CTE (20°C)
5.89 μm/m-°C
3.27 μin/in-°F
Measured at 25°C
Linear CTE (250°C)
6.3 μm/m-°C
3.5 μin/in-°F
Linear CTE (500°C)
6.9 μm/m-°C
3.83 μin/in-°F
Specific Heat Capacity
0.285 J/g-°C
0.0681 BTU/lb-°F
Thermal Conductivity
22 W/m-K
153 BTU-in/hr-ft²-°F
Melting Point
1852°C
3370°F
Optical Properties
Property
Metric
English
Notes
Emissivity (0-1)
0.32
0.32
650 nm; unoxidized pure Zr sample; total
Key Features & Applications
Corrosion Resistance: Excellent in aggressive media (e.g., acids, high-temperature water), making it ideal for chemical processing and nuclear industries.
Formability: Balances strength and ductility, suitable for fabrication into sheets, tubes, and complex components.
Typical Uses: Chemical processing equipment, heat exchangers, nuclear reactor cladding, and marine applications requiring corrosion resistance.
