The localized corrosion occurred on SUPER304H steel tubes used for boilers of units under construction in coastal areas has been analysed by using macroscopic examination

chemical composition test

metallographic detection

scanning electron microscope

and energy spectrum.Results show that the main cause leading to localized corrosion on SUPER304H steel tubes is due to chlorine ions.For this

it is recommended that the said steel tubes should be covered with canvas during sea transportation and storage

and being protected with corroson inhibitors.The tube materials

which are already being corroded

should be rubbed

and examined through liquid penetration test and wall thickness measurement

after reaching acceptable level of quality

just then they can be normally used.