The effect of laser transformation notching on the controlled fracture of a high carbon (C70S6) steel

Obtaining a sharp crack effect from a LTN is attributable to a combination of: (a) the presence of brittle martensite, (b) intergranular cracking of favourably oriented columnar grains after melting with inclusions and defects at their boundaries, (c) intergranular cracking of coarse grains produced by a high austenitising temperatures and (d) minor or major cracks sometimes resulting in centre-line cracking which arises during solidification. LTN was thus shown to have the potential to lead to an effective means of obtaining consistent fracture splitting of connecting rods.