Failure Investigation of a Boiler Pipe

The damaged boiler pipe from the cochran horizontal pipe type boiler was investigated to study the cause of its failure. The damaged pipe having a through hole of about 4mm size was studied from both water and fire side with the help of visual inspection, physical measurements, optical micrograph, x-ray diffraction (XRD) and Electron probe microanalysis (EPMA).It was concluded that water side corrosion was more predominant than the fire side corrosion in reducing the thickness of the plate and eventually causing a through hole. The higher rate of corrosion from water side may he attributed mainly due to the presence of large amount of inclusions which led to preferential dissolution of matrix around them. The water side corrosion product was non adherent, fragile and powdery whereas fire side corrosion product was adherent