Stress Corrosion Cracking Analysis of a 304 Stainless Steel Three-way Pipe in a Gas Turbine Power Plant

A 304 stainless steel three-way pipe in a gas turbine power plant cracked and induced a leakage. Stereoscopic microscopy, optical microscopy, spectrometer, SEM and EDS were adopted to do the macro and micro analysis of the three-way pipe. Results indicate that the crack was biforked. There were a large area of mud patterns on the fracture and the corrosion products contained high concentration chloride ion. All these facts proved that the crack was caused by stress corrosion cracking. Besides, the corresponding prevention and improvement measures were proposed as well.