Iron Matrix Transformations and Mechanical Properties of Fe-25Cr-C-B Eutectic Cast Alloys

Abstract

Iron matrix transformation behavior and high temperature strength of Fe-25mass%Cr-C-B cast alloyswere investigated using thermal expansion method and compressive test, respectively. Five kinds of eutecticalloys were destabilized at temperatures of 1173 K, 1273 K and 1373 K for 1800 and 18000 seconds, followed with air cooling. Compressive test was made on Fe-25Cr-OC-2.2B, Fe-25Cr-2.2C-1.0B and Fe-25Cr-3.5C-OB eutectic alloys at temperatures up to 1073 K. Result of the work shows that Ms temperaturerises with the decrease in destabilization temperature, but the hardness becomes larger with the increase indestabilization temperatures, for the alloys with boron content. Compressive strength of all as-cast alloyswas above 2000 MPa at room temperature and above 100 MPa even at 1073 K. The true stress-true straincurves characteristics depended on the chemical composition of the alloys. The effect of destabilization heattreatment almost disappears at the temperatures above 873 K in every alloys.