Abstract
CMnSi steel grades with carbon contents ranging from 0.2 to 0.3 wt% and manganese contents of 3 and 5 wt% were Quenched and Partitioned (Q&P). Tensile properties were assessed and retained austenite fractions measured. Intercritically annealed and fully austenitized conditions were studied. The best combinations of tensile strength and total elongation obtained in the 0.2C–3Mn–1.6Si grade after intercritical annealing were associated with strength levels in the 1000–1200 MPa range and total elongations ranging from 14 to 20%. Optimum properties were obtained in the 0.3C–3Mn–1.6Si steel after full austenitization with tensile strength levels ranging from 1450 to 1700 MPa and total elongations ranging from 11 to 18%. The 0.2C–3Mn–1.6Si fully austenitized samples also exhibited remarkable strength/ductility combinations albeit at lower strength levels of 1200–1450 MPa UTS with 9–15% total elongation indicating the effectiveness of the manganese addition to develop novel property combinations.
