X-Ray and Age-Hardening Studies on Certain Iron-Cobalt-Chromium Alloys

摘要

Iron-cobalt-chromium alloys containing around 60 per cent iron and varying amounts of chromium wore studied under a variety of heat treatments by means of X-ray diffraction and hardness measurements. Small amounts of Cr (or even Mo) below 5 per cent do not alter the body-centered alpha iron structure except for lattice dimensional changes. Amounts of Cr in excess of 6 per cent produce face-centered cubic alloys of greater ductility which do not age-harden. The age hardening characteristics of alloys containing up to 10 per cent Cr were studied and a partial phase diagram for this alloy series was drawn up. With iron and cobalt in approximate ratio, Fe:Co2, a complex oxide forming on these alloys at 1000 degrees F has a composition FeCo2o4, as determined by diffraction studies.