Evaluation method of brittle crack propagation stopping performance of thick steel plate

摘要

A method for evaluating the brittle crack propagation stopping performance of a thick steel plate is provided. The present invention is a method for evaluating the brittle crack propagation stopping performance of a thick steel plate using a large specimen, and a notch that generates a brittle crack is formed at one end of the center portion in the load direction of the large specimen. Further, an embrittled region having a predetermined length L is formed at the tip of the notch or so as to include the tip and extend in the brittle crack propagation direction, and further, the embrittled region is formed. Later, at least one test piece is used in which the fusion weld is separated from the embrittlement region. The fusion weld is located at a position spaced from the embrittlement region on one or both sides by a distance d related to the plate thickness t, and the length is ΔL1 (0.3L to -0.3L) with the embrittlement region length L as a reference. ), And a shape shortened from the end of the test piece within a range of ΔL2 (0 to 0.4 L). Thereby, the brittle crack generated from the notch propagates without deviating from the predetermined brittle region, FPD can be prevented, and an effective CAT test result can be obtained.