| Abstract: | The tensile curves as well as original and selective dissoluted fracture surfaces have been studied. The function of the γ' phase on the mechanical properties of the steel has been investigated. The fracturing process consists of: formation of dimples – formation of splits in dimples – the splits in dimples join each other to form secondary cracks – formation of inner lips and tiny dimple regions. The morphology of fracture looks like ridges and peaks. It is considered that the column boundaries in ingots may split easily; this causes bedding fracture and the degradation of Z–direction properties. The formation of bedding fracture is affected markedly by heat treatment and tensile temperature. Some ways of improving mechanical properties have been discussed. |
