Portevin-Le Chatelier (PLC) instabilities and slant fracture in C-Mn steel round tensile specimens

Abstract : Round tensile specimens of a C-Mn steel were tested at different strain rates and temperatures. Some of the samples tested in the Portevin-Le Chatelier (PLC) domain exhibit slant fracture surfaces. Spherical dimples were evidenced all over the slant fracture surfaces. Numerical simulations showed that stress triaxiality increases around PLC bands and that slant fracture occurs within a PLC band. In a round specimen, this band is plane and inclined, whereas some numerical results predict conical bands.