THE EQUILIBRIUM DIAGRAM OF THE TERNARY SYSTEM, IRON-CHROMIUM-COPPER.

Abstract

The alloys of iron, chromium and copper containing less than 40{%}Cr and 40{%}Cu were investigated by means of the thermal analysis, dilatation measurement and microscopic exami- nation, and an equilibrium diagram of the ternary system is herein proposed. In this system there exists no intermetallic compound and a nonvariant reaction, liquid +$γ$ 〓 $α$+C, takes place at 1,085°C. The domain of $γ$-phase in Fe・Cr・System is enlarged by addition of cop ?? er, so that the alloy containing 14{%}Cr and 5{%}Cu consists of homogeneous $γ$-phase at high temperature, and the specimen with 19{%}Cr and 4{%}Cu, $α$- and $γ$-phases. As the chromium content increases, the solubility of copper in $γ$-iron and the copper content at eutectoid composition dec- rease at first and then increase, whilst the eutectoid temperature rises gradually and afterwards rapidly