ESTIMATION OF TOUGHNESS BY NON-DESTRUCTIVE INSPECTION

摘要

PROBLEM TO BE SOLVED: To estimate the toughness of SCS24 cast steel or SCS24 corresponding steel used in a water wheel runner or pump impeller used in an actual machine. SOLUTION: This estimation method comprises a process for producing a plurality of test pieces different in toughness to calculate the toughness of these test pieces, a process for forming in advance on estimation curve showing the correlation between the grain boundary carbide length to a grain boundary length and a toughness value, a process for sampling the replica of a metal structure from a member wherein toughness is desired to be calculated and the test pieces cannot be sampled, a process for calculating the length ratio of grain boundary carbide to the boundary length, and a process for estimating toughness from the length ratio to the grain boundary length of grain boundary carbide and the estimate curve.