Abstract
In order to estimate and predict the strength of cast or welded structural materials at 4K, the mechanical properties of columnar parts of cast austenitic stainless steels were investigated. Compared with hot-rolled materials, the mechanical properties of cast materials at 4 K were rcduced to 65-84% in tensile properties and 26-36% in absorbed energy. Fracture surface of tensile and impact specimens at 4 K showed the reained dendrite morphology and cracks were observed in matrix. The impact properties of cast materials at 4 K were improved by solution heat treatment. The mechanical properties of cast materials were affected by not only delta-ferrite content but also solidification structures
