zirconium alloys are composed of 95.5%to 99.2% zirconium and hafnium with a maximum hafnium content of 4.5%. Zirconium mill products are available in two chemical grades each sharing excellent corrosion resistance and also having slightly different physical and mechanical properties. Zirconium 702 is commercially pure zirconium.zirconium 705 is zirconium alloyed with niobium to increase its strength and improve its formability.One of the major applications for Zr is as a structural material in the chemical processing industry. Zr exhibits excellent resistance to corrosive attack in most organic and inorganic acids, salt solutions, strong alkalis, and some molten salts . In certain applications, the unique corrosion resistance can extend its useful life beyond that of the remainder of the plant