Accession Number : AD0654807

Title :   RESEARCH INVESTIGATION OF CORROSION-RESISTANT MATERIALS FOR ELECTROCHEMICAL CELLS.

Descriptive Note : Final rept. Jan 66-Jan 67.

Corporate Author : TRW SYSTEMS REDONDO BEACH CALIF

Report Date : JAN 1967

Pagination or Media Count : 97

Abstract : The compatibility of highly corrosion-resistant metals and alloys with molten salt and hot phosphoric acid electrolyte systems was studied. Probes suitable for use with the electrical-resistance method in molten salt electrolytes were developed. The probes made from 304 and 316 stainless steels were tested in KCl and KCl-NaCl at temperatures of 820 C and 700 C, respectively. The probes of 316 stainless steel showed fair reproducibility in corrosion rates when the probes were prepared and tested under similar conditions. The electrical-resistance method was found to be equally applicable for evaluating material compatibility in hot, concentrated phosphoric acid. The pure metals Ta, Ni, and W, as well as Ni- and W-based alloys, were investigated. Ta and Ta-10W alloy exhibited corrosion rates less than 1 mpy. Pure W and Hs alloys, W-25Re and 40Mo-30Re-30W, were also resistant to concentrated phosphoric acid with corrosion rates between 1 to 6 mpy. The results also indicated the potential gains that can be achieved by exploring a large number of alloy system and its composition range. The diffusion block concept of preparing a large number of alloy combinations in a systematic manner was thus conceived and tested. (Author)

Descriptors :   (*CORROSION RESISTANT ALLOYS, COMPATIBILITY), (*METALS, CORROSION RESISTANCE), ELECTROLYTES, PHOSPHORIC ACIDS, STAINLESS STEEL, TANTALUM, NICKEL, TUNGSTEN, NICKEL ALLOYS, TUNGSTEN ALLOYS, TANTALUM ALLOYS, IRIDIUM ALLOYS, RHENIUM ALLOYS, NIOBIUM, MICROSTRUCTURE, MOLYBDENUM ALLOYS

Subject Categories : Non-electrical Energy Conversion
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE