Abstract
In order to study a mechanism of hydrogen induced blistering cracking (HIBC), a new broaband (<10MHz) acoustic emission (AE) monitoring and signal processing for AE source inversion were utilized. The monitoring system developed was applied to measure the outplane displacement of elastic waves produced by a fast dipole phenomenon and to compare with the displacement numerically computed for a point of dilatation and cracking. The AE signals, indicating the point of dilatation with an extremely short rise time of source signal were reproducibly measured during the hydrogen charge to the steel plate with segregation band and low carbon steel rod. The AE source location estimated by the multichannel monitoring system agreed fairly well with the that of characteristic HIBC occurrence in several experiments. Possible mechanisms for hydrogen gas explosion due to a hydride or hydrogen cluster assisted by internal potential fluctuations were discussed.
