Zirconium is a polymorphic, silvery-grey, ductile metal with high corrosion resistance. It exhibits a strongly pronounced anisotropic thermal expansion behaviour. Mechanical properties of zirconium are very susceptible to interstitial impurities. Their presence in metal in the form of solid interstitial solutions leads to a noticeable increase in ultimate and yield strengths and, especially at low temperature, leads to plasticity reduction. More than 90% of the produced zirconium and its alloys are only used as a structural material in atomic power engineering. The metal is used in the manufacture of fuel cladding, coverings and other parts of fuel assemblies. It is also applied in the manufacture of pressure tubes for thermal-neutron reactors. In this regard, zirconium is solely considered in terms of its use in the reactor building and with regard to the conditions originating in nuclear reactors. However, zirconium is widely used as a material, which improves anticorrosion properties by coating. Among the basic methods of coating zirconium on steel are electrolytic one and that of immersion in a melt. Zirconium coatings are characterized by corrosion resistance in atmospheric conditions, in fresh water and in an enclosed space by moderate humidity. Zirconium is also used as an alloying element. Stainless steel alloying zirconium has a granular structure and, by varying zirconium content, it is possible to obtain steel with necessary grain size.
Performance of zirconium electrolytic-plasma treatment and polishing:
Recommended processing time for zirconium polishing — 180 sec.
Grinding and deburring speed — 30 sec.
Average time to reduce the roughness value by 1 class — 75 sec.
The number of polishing cycles before changing the electrolyte — 150.