Abstract：The tube bundle of one rotary dryer with moisture regulating steam in a coking plant was cracked in the process of operation. The failed steel pipe was analyzed by the means of chemical composition, metallographic microscope, scanning electron microscope and energy dispersive spectrum. According to the test results of macro and micro fracture morphology, microstructure, corrosion pit and mechanical property, it was found that the failure reason of steel pipe was stress corrosion cracking. The crack was originated from the pitting corrosion on the surface of steel pipe, and the stress was from the thermal stress generated when the steel pipe was subjected to alternating low and high temperature.
2022, Vol. 40 
