Lifetime in Steel Code Wire Drawing Dies of WC-Co Cemented Carbide Containing TaNbC or Cr₃C₂

Abstract

Wire drawing dies and specimens of WC-Co cemented carbides containing TaNbC or Cr₃C₂ were fabricated by hot isostatic press (HIP) treatment at 1633 K in 40 MPa Ar and by anneal treatment 1593 K in vacuum. The lifetime of steel code wire drawing were evaluated for the dies and mechanical properties such as hardness, transverse-rupture strength and fracture toughness were examined for the specimens. It is noted that the lifetime of drawing die was remarkably improved by the anneal treatment for both of TaNbC and Cr₃C₂ containing WC-Co cemented carbides. The TaNbC containing alloys showed longer lifetime than the Cr₃C₂ containing alloys. The lifetime of drawing die had weak relationship to hardness, but seemed to have no correlation with strength and toughness. The remarkable improvement of drawing die lifetime by the annealing treatment after HIP and the longer lifetime for TaNbC containing alloys can be understood from the viewpoint of adhesion strength between WC and Co phase affected by alloy content and heat treatment of cemented carbides.