MECHANICAL PROPERTIES AND CORROSION RESISTANCE OF ZIRCONIUM AND ITS ALLOYS IN WATER, STEAM AND GASES AT ELEVATED TEMPERATURES

In the development of commercial alloys, suitable for continuous operation in pressurized water and steam, the following alloys were studied: zirconium--niobium, zirconium--nickel, zirconium--tin, zirconium--iron, zirconium- -tantalum, zirconium --niobium--tin, zirconium--niobium--tantalum, zirconium--tin- -iron-nickel, zirconium-tin-- iron-- niobium --nickel, and a number of others. The purity of primary zirconium, following processes of melting and other treatment, as well as the condition of the surface has a profound influence on the properties and on their absolute values. Corrosion tests in water and steam were carried out, mainiy under static conditions in distilled water. Corrosion tests in gases were carried out in a glass vacuum apparatus loby means of a volumetric method, also in sealed glass capsules with various gases held in thermostatic conditions at the test temperature. Corrosion tests were followed by mechanical testing. The results of corrosion study of alloys in water and steam made it possible to determine alloy groups, which are stable under continuous operation at various temperatures. As a result of research in gases, quantitive data were gathered dealing with the kinetics of interaction with zirconium and its alloys. The change of the mechanical properties of the more » alloys, when affected by gases, was also obtained. (auth) « less