抄録
The characteristics of hydrogen embrittlement for two kinds of ADI in the absence of retained austenite (austempered ductile iron precipitated ferrite around graphite or α-ADI, and annealed at 673K for conventional austempered ductile iron or ADI-AN) were examined. Specimens were tested for embrittlement by dropping a water-based solution of 0.365%HCl at 0.013ml/s intervals using a cantilever type apparatus. After an extended period of time under sustained high bending stress, α-ADI and ADI-AN fractured with creep deflection. ADI having retained austenite was abruptly fractured without creep deflection in HCl solution. This suggests that the hydrogen embrittlement for ADI may be caused by the retained austenite in ADI.
