Abstract
The stress corrosion cracking (SCC) of type 304 stainless steel during a creviced bent beam (CBB) test in a high-temperature, high-pressure water environment was monitored by an optical fiber acoustic emission (AE) sensor. By examining the number and type of cracks formed by different durations of CBB testing an SCC initiation and propagation behavior model was developed. This model was then used to examine the AE event rate, which was found to agree well with the observed changes in the number and size of the cracks formed. Through analysis of the relationship between crack size and AE, the weaker AE signals were assumed to be produced by the initiation of small cracks, whereas the coalescence of cracks produces moderate and large AE signals. On the basis of these findings, it is concluded that the SCC propagation behavior can be reliably estimated from the event rate and amplitude of AE signals.
