| The purpose of the present study was to investigate the fracture behavior of low carbon steels during wire drawing. In ferrite-pearlite steels, cracks were initiated at the interfaces of pearlite nodules and ferrite-pearlite, and at cementite precipitated along the grain boundaries. In steel containing martensite, cracks were initiated by decohesion of ferrite-martensite interface and by shear fracture of martensite particle. Crack initiation behavior appeared to be related to the degree of plastic deformation of constitutent phases, i.e. ferrite, pearlite and martensite. During wire drawing, cracks initiated at ferrite-martensite interface were propagated as characteristic conical shape by the coalescence of small cracks, resulting in final failure of cuppy fracture. |
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