Methods for assessing the grooving corrosion of high-frequency electric resistance welded pipes

Grooving corrosion is a major form of corrosion and is prone to occur when high-frequency electric resistance welded (HFW) pipes are being used.Therefore,grooving corrosion is one of the performance indexes of HFW products.Grooving corrosion usually occurs along the welding fusion line,resulting in one or more corrosion grooves.The main factors affecting grooving corrosion include the contents of alloying elements and impurities (especially sulphur) in the steel,the microstructure of the welds and the steel substrate,welding parameters and the service environment as well.In this study,the existing methods for assessing grooving corrosion were systematically reviewed,improvements and new methods were proposed and developed to overcome the shortcomings of the existing methods,such as inaccuracy and excessive research time.By comparison with the existing methods,the operational procedures and the characteristics of the new methods are introduced,and issues regarding the behavior of grooving corrosion and their assessment methods,which both need further research,are discussed in this study.