Directing against the cracking leakage fault occurred on the water-wall of 410 t/h boiler in one power plant

the macroscopic inspection

chemical element analysis

tension test

metallurgical analysis.Scanning electron microscope and energy spectrum analysis have been carried out.Results show that the cracking leakage on water-wall was resulted from hydrogen corrosion

because the water used in hydraulic test during the process of manufacture was polluted

resulting in deposition of Cu ions in water onto the water-wall tubes

making the inner surface of tube-wall to produce electro-chemical corrosion

and further resulting in hydrogen corrosion.