Embrittlement characteristics of fracture toughness in ductile iron by contact with water

Several ductile Iron samples with various kinds of matrix were subjected to fracture toughness testing in a condition that specimens were in contact w ith water at the time of testing. A considerable reduction in fracture toughness caused by contact with water was found in the case of the samples with an austempered matrix or a quenc hed-&-tempered matrix. However this embrittlement behavior was hardly notic eable in the case of the samples with a fully ferritic matrix or a mostly f erritic matrix. This embrittlement behavior is considered to be induced by hydrogen embrittlement.