Zirconium

Zirconium is an element (Zr- Atomic Number 40, AtomicWt 91.22)

  • Usually alloyed with Hafnium (4.5%)
  • Grade 702
    • UNS R60702
  • grade 705 with Niobium (Ni 2.5%)
    • UNS R60705
  • ASTM B752
    • 702C equivalent to UNS R60702
    • 705C equivalent to UNS R60705

Typical Properties


  702  705 
Tensile   379  413 min N/mm2
Yield 207 241 min N/mm2
Elongation 16% 14%
Density  6.5   6.6 g/cm3
P/T rating 702 SPT03 15.6 bar class 150
P/T rating 705 SPT05 19.8 bar class 150
              

Corrosion Properties

  • Good in nearly all cases, excellent for high temperature acids
  • Estimated >20 year life on seawater (heat exchanger tubes at 200 oC
  • Some fouling performance but immune to Microbiological Corrosion

Comments & Cautions

  • Moderate strength, low density compared to steels
  • Brittle- stamping to be avoided
  • Casting is a specialist process
  • Low modulus of rigidity (99 N/mm2)
  • Pyrophoric- caution on machining
  • Flanges need special design consideration, especially if use is at higher temperatures & flanges raised face
  • Galling and wear properties not good