Progress reported includes the selection of 15 ternary bases for further study in steam or water. About 75 compositions were prepared and are being arc- melted for fabrication into corrosion specimens. Investigations of Zr purity and heat treatment effects on corrosion are being continued. Included are data from corrosion tests on binary alloys with superheated water and steam, and a list of alloys for initial investigation based on results of corrosion screening tests. (J.H.D.).

Corrosion data for zirconium alloys exposed to 680 deg F water for 336 hr are presented. For this exposure time, all specimens exhibited the desirable tenacious, black oxide coating. Preliminary studies were made of the transformation kinetics of Zr-30 Nb, Zr-30 Nb-1 Mo, and Zr30 Nb-3 Mo alloys. Hot rolling these ingots at 1550 deg F resulted in severe edge cracking and excessive air contamination. Nevertheless, small specimens were betaquenched from 1000 deg C and isothermally transformed at 680 and 750 deg F. Hardness versus transformation time curves did not show the relatively sharp hardness increase which signifies the beginning of beta transformation. Corrosion specimens are being prepared for investigation of the effect of zirconium purity on corrosion resistance. (M.C.G.).

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.).

Specimens which previously showed promising corrosion resistance in 750 deg F steam sfter 329 hr exposure were reentered in test for an additional 480 hr. Additional tin alloys were included. The compositions Zr--0.5 Nb, Zr-IV, and Zr-- 1 Sb and the alloys Zr--Fe, Zr--Cr, and Zr--Mo appeared the most promising. The corrosion resistance of Zr--Sn alloys was not sufficient to consider the alloy for further development. (M.C.G.).

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.).