Influence of microstructure and manganese content on the mechanical properties of cast irons with spheroidal graphite

Fracture Toughness of Nodular Graphite Cast Irons Under Static, Impact and Cyclic Loading

“…5(b)]; manganese has a negligible effect for ferritic cast irons. Figure 5 also shows the results from Refs[lO, 1 I] (open symbols). Pearlite content exceeding 60% drastically lowers the fracture toughness of the material, as is seen from Fig.…”

“…With an increase in temperature plastic deformation preceded fracture of the specimen and a maximum plastic crack opening displacement was observed at room temperature. For 20 mm-thick specimens equation (1) was not satisfied at T > 213 K. For 10 mm-thick specimens essential plasticity was noted even at 173 K and plane strain conditions were not satisfied over the whole temperature range. Test results for nodular cast iron IT are presented in Fig.…”

“…At T 3 293 K minute plasticity appeared and in this case equation (2) was satisfied only for some specimens. Plane strain condition (1) was not satisfied at T > 208 K. Ductile fracture was observed with 10 mm-thick specimens at temperatures as low as 213 K, while equation ( I ) was not satisfied at T > 150 K. The results of nodular cast iron TI1 fracture toughness testing under static loading are presented in Fig. l(c).…”

“…l(a). The limits within which equation (1) conditions are satisfied for the corresponding specimen thickness are indicated. For nodular cast iron I T load vs deflection curves of two types were obtained.…”