Failure analysis of a head gear pulley used in coal mines

This investigation was primarily aimed to examine the probable causes of in-service failure of head gear pulley used in colliery. Preliminary visual examination, dimensional measurement, chemical analysis and estimation of mechanical properties were necessary supplement to this investigation. Optical microscopic analysis along with Scanning Electron Microscopy (SEM) examinations were carried out at the three locations namely rim, hub and spoke to understand the metallurgical reasons for failure. Detailed stress analyses of these three regions were also carried out. Finally, it was concluded that the rim failed first due to inferior quality of material and significant deviation from the specified geometry of the rim cross section.