Abstract
It is very difficult to produce heavy section cast steel without any defect, but defects may become the starting point of brittle fracture. In this paper, initiation characteristics of brittle fracture were investigated using “Three Point Bending” type COD Test to ascertain safety of cast steels. Bending COD Test is effective as a small size KC test and good coincidence is found between the results of Bending COD Tests and Deep Notch Tests. Critical COD and KC values were measured at the center of cast steel of 400mm thickness and the relation between applied stress and defect size to prevent brittle fracture was elucidated.
