1. Precipitation of ferrite in hypoeutectoid steel in the form of large needles and plates with a specific orientation lowers the fracture toughness. 2. The fracture toughness of steel 35 with excess ferrite in the form of thin needles growing from a boundary network is at the same level as (or somewhat higher than) the fracture toughness of samples with equiaxed ferrite. 3. Increasing the percentage of quasieutectoid and reducing the grain size by rapid cooling compensate the harmful effect of Widmanstatten ferrite on the fracture toughness of steel 35. © 1979 Plenum Publishing Corporation.
