MONITORING OF MICROCRACKING EVENTS IN WELD THERMAL SIMULATED MICROSTRUCTURES USING ACOUSTIC EMISSION

摘要

Monitoring of microcracking events in two different weld thermal simulated microstructures of an API X65 pipeline steel is performed using acoustic emission. In the intercritically reheated coarse grained heat affected zone (ICCGHAZ) significant acoustic activity was observed prior to maximum load in the specimens. For the coarse grained heat affected zone (CGHAZ) the acoustic activity was much less significant. The results lend support to the multiple-barrier model for cleavage fracture in steels, but points in the direction that the cleavage fracture initiation mechanisms will be depending on the microstructure.