Studies on Zr-Cu-Mo base alloy, (2). The effects of the fourth alloying elements on the mechanical properties and the corrosion resistance of Zr-Cu-Mo alloys in CO₂

The effects of the fourth elements on the alloy have been investigated in order to improve the mechanical properties and the corrosion resistance of Zr-Cu-Mo alloys at high temperature and high pressure of CO₂. Results obtained are summarized as follow: (1) Nb and Bi are excellent as the fourth element of alloying. (2) The desirable good properties are found in these alloys of Zr-0.5% Cu-1.0% Mo-1.0% Nb and Zr-0.5% Cu-1.5% Mo-1.0% Bi. (3) These alloys have better mechanical properties than ternary alloys and also these properties are much more improved by the heat-treatment. (4) These alloys have the good corrosion resistance in high temperature and pressure of CO₂ in both cases of as annealed and after heat-treated state. No break away phenomenon is occurred after 2,000 hr reaction with CO₂ under pressure of 20 Kg/cm² at 450℃. (author)