Chain Graphitization of a Failed Reheater Tube
A vertical straight-run reheater tube was received for failure analysis. The tube was specified as 2.50” OD x 0.180” MWT, SA-209 T1A C-Mo Steel. It had been in service for 38 years. The failure was a thick-edged circumferential crack which propagated in a spiral about the longitudinal axis. These features are typical of a chain graphitization failure.