Development of an Acoustic Emission Monitor and Monitoring Techniques for Long-Term Monitoring of U-0.8Ti Electron-Beam Weldments for Postweld Cracking

摘要

An acoustic emission (AE) monitor and data analysis techniques have been developed for long-term monitoring to detect delayed weldment cracking. The monitor, which comprises multiple identical channels of standard electronic instruments, is capable of measuring the total AE activity in a weldment and the relative energy content of individual AE pulses. The monitor was used to detect the onset of hydrogen-assisted cracking (HAC) in U-0.8Ti electron-beam weldments. Use led to the conclusions that the monitor is adequate to study delayed-cracking phenomena, such as HAC; weldments of the U-0.8Ti alloy do produce AE after welding and intensive AE production coincides with the appearance of macrocracks and their extension; the time-dependency of HAC can be determined from the AE record; and the monitor is a valuable tool for studies of delayed-cracking behavior, such as HAC and stress-corrosion cracking. Recommendations are made to upgrade the monitor to enhance utility and data analysis efficiency and to use the monitor in stress-corrosion cracking studies. The monitor is in regular use on continuing studies of HAC in several alloys. 3 refs., 4 figs. (ERA citation 12:050066)