Publication

Abstract : >Coiling of steel sheet is one of the easiest methods adopted by steel mills for the compact transportation of bulk sheet material to truck manufacturers for making 'C' shaped side frame rails. The coiling-uncoiling operation induces residual stresses in the steel sheet due to plastic strain hardening. This initial imperfection in the form of residual stresses remains in the plain web and flange areas of the rail sections. In corner areas of frames, increase in residual stresses are observed due to severe plastic deformation from forming operation than the coilinguncoiling operation. More accurate consideration of the residual stresses becomes necessary when the behaviour of truck side frame rail web and flange sections, derived from different coil diameters are assessed. In this work, micro-hardness measurement is employed to predict the extent of plastic deformation at different coil diameter locations. The residual stresses induced by the coiling-uncoiling operation is assessed using the X-ray diffraction technique for steel coil diameters ranging from 600 mm to 1800 mm. Fatigue tests on samples extracted from different coil diameters indicate that fatigue life increases with the increase in coil diameter of the sample. The fatigue life of the annealed flat test sample was found to be higher than the fatigue life of samples derived from different coil diameter locations of steel coils received from steel mills