On the basis of 4800 hr exposure to 680 l F water, a number of ternary compositions were shown to have corrosion resistance superior to Zircaloy-2. In addition, the strength and hydrogen pickup properties of the alloys were generally improved over Zircaloy-2. The promising alloys were based on the binary materials Zr- 1Sb, Zr- 1Cr, Zr0.5Nb, and Zr-0.5Sn to which small percentages of Te, Ge, Cr, or Fe were added. At present, 680 l F water corrosion data for an exposure time of 5000 hr are available for the modified ternary alloys. Development of materials for potential service in 750 and 900 l F steam proceeded in a manner similar to that for 680 l F water application. On the basis of corrosion resistance and strength, the alloys Zr3Cr- 1Fe, Zr-3Cr- 0.25Te, and Zr- 1V- 1Fe were considered highly promising and initially acceptable. However, hydrogen pickup properties, which were about the same as Zircaloy-2, were judged as unacceptable. In an attempt to improve this characteristic as well as to further enhance corrosion resistance and strength, an additional series of ternary alloys was prepared. The compositions studied in 900 l F steam did not exhibit satisfactory corrosion resistance. (P.C.H.).

The oxidation of the following zirconium alloys in water at 680 deg F is reported: Zircaloy-2, Zr--Cr-- Te, Zr-Nb-Te, Zi--Sn-Te, Zr--Sn-Ge, Zr--Sb-Ge, Zr-- Sb-Te, and Zi-Sb--Nb. The tensile properties of Zircaloy-2, ZrCr-Te, and Zr-Nb-- Te alloys at room temperature and 680 deg are given. (N.W.R.).

Corrosion testing data are presented for a large number of Zr alloys in 68O deg F water (1043 and 1902 hr), 750 deg F steam (329 hr), and 900 deg F steam (97 hr). These alloys include Zircaloy-2 and Zr alloyed with Nb, Sn, V, Sb, C r, Cu, Fe, Si, W, Mo, Ta, Co, Pt, Pd, Rh, As, Bi, Te, Ge, Ag, and Ni. Tensile test data are also reported for ten of these alloys at 68O deg F; these alloys are Zr alloyed with Nb, Sn, Fe, V, Cr, Mo, Sb, and Co, in addition to unalloyed Zr and Zircaloy-2. (D.L.C.).

Experiments concerned with the development of zirconium-base alloys having corrosion resistance and strength superior to Zircaloy-2 and/or the development of materials of equivalent corrosion resistance but exhibiting enhanced strength are presented. After 3000 hr exposure to 680 deg F water, binary zirconium alloys showed corrosion resistance superior to Zircaloy-2. Alloys considered promising and which offer the highest chance of success are based on the binary compositions Zr--1Cr, Zr--ISb, Zr--O.5Nb, and Zr--O.5Sn with small additions of Te, Ge, Cr, or Fe. Alloys containing relatively high percentages of solute elements did not exhibit satisfactory corrosion properties. Corrosion data on experimental alloys in 750 deg F steam indicate a few highly proising and initially acceptable materials, which are Zr--3Cr --lFe, Zr--3Cr-- 0.25Te, and Zr--lV--lFe. Thus far the corrosion resistance is better than Zircaloy-2 and the higher alloy content indicates enhanced elevated temperature strength. (P.C.H.).