Failure of a Stainless Steel Shell of a High Temperature Vessel

This presentation is a case study that involved the rupture of a shell from a vessel that operated at a high temperature. The case study involved determining the failure mechanism that resulted in the rupture and characterizing the vessel material to understand the scope of the damage to the vessel. The characterization methods used included visual examination, scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) examination, microstructure examination, chemical analysis testing, hardness testing, and impact testing. During the repair process, additional temperature-monitoring equipment was installed. When the equipment was restarted, the vessel was found to be operating at a higher-than-expected temperature.

One novel aspect of the material characterization included use of a broad beam ion mill when examining the vessel's base material microstructure for voids. The broad beam ion mill enabled faster SEM characterization of features that could have been small voids than was able to be achieved with mechanical polishing alone.