No abstract

This report wos prepared as on occount of Government iponsored work. Neither the United States, nor the Commission, nor ony person acting on behalf of the Commission:A. Malces any warranty or representotion, expressed or implied, with respect to the accuracy, completeness, or usefulness of the Information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of ony information, apparatus, method, or process disclosed in this report.As used in the above, "person acting on beholf of the Commission" includes any employee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, ony information pursuant to his employment or contract with the Commission, or his employment with such contractor.

No abstract

The oxidation resistance of thin sheets of iron-28 w/o chromium-2.67 to 10.0 u>/o aluminum alloys, nominally 0.004, 0.006, 0.008, 0.012, and 0.016 in. thick, was determined by exposure in static air for 100 hr at 2100 and 2300 F. A minimum of 3.67 and 9.37 w/o aluminum was necessary to prevent excessive oxidation of 0.004-in.-thick sheet material at 2100 and 2300 F, respectively. Correspondingly, specimens of lower aluminum content and greater thickness withstood the oxidation attack. Oxidation of iron-chromium-aluminum alloys appeared to he related to the diffusion of aluminum to surfaces of the sheet to form an adherent protective layer of Al20o.

The elevated-temperature tensile properties of zirconium and of Zircaloy 2 were investigated and the creep properties were determined at temperatures up to 500 C. The effect of time at test temperature on the tensile strength of the 25 per cent cold-worked materials was investigated. The increased tensile strengths of cold-icorked zirconium and Zircaloy 2 were reduced to that of the annealed material by holding at 500 C for approximately 90 and 200 hr, respectively. Cold-worked Zircaloy 2 tested in creep had superior 1000-hr rupture strengths for all test temperatures, except 500 C, At 500 C, the 1000-hr rupture strength of the cold-worked material reverted to that of annealed Zircaloy 2 at the same temperature. The stress to produce a creep rate of 10 per cent per hr in the annealed Zircaloy 2 mas 25,000 psi at 150 C and 3200 psi at 500 C. Hydraulic-bursting tests also were made on seamless Zircaloy 2 and on welded zirconium tubing. The bursting pressures were considerably higher in the seamless tubes than in the welded tubing, 6800 psi as compared with 5400 psi at room temperature and 3150 psi versus 2200 psi at 400 C. The welded zirconium tubing failed at the longitudinalseam weld under hydraulic pressure.