Effect of W Content on Microstructure and Properties of Fe-Cr-Co Alloy

Fe-Cr-Co alloys with different W mass fraction （0, 4.5%, 6.5%, 8.5%） were prepared by vacuum arc melting, cold rolling and 1 200 ℃×2 h annealing. The effect of W content on the microstructure and properties of the alloys was studied. The results show that when the mass fraction of W was not higher than 4.5%, the test alloy had a single body-centered cubic （BCC） structure. When the mass fraction of W was 6.5% and 8.5%, the alloy exhibited a BCC + face-centered cubic （FCC） dual-phase ordered structure, and the FCC structure phase increased with the increase of W content. After adding W element, the hardness, tensile strength, yield strength and uniform elongation of the test alloy increased; with the increase of W content, the hardness first decreased and then increased, the tensile strength and yield strength first increased and then decreased, and the percentage elongation after fracture increased. When the mass fraction of W was 6.5%, the alloy had excellent mechanical properties; the hardness, tensile strength, yield strength and percentage elongation after fracture were 398.8 HV, 1 108.32 MPa, 267.232 MPa and 16.747%, respectively. The resistivity of the alloy increased after adding W, but with the increase of W content, the resistivity decreased. The resistivity of the alloy with 4.5wt% W was the highest, which was 125.28 μΩ·cm.