A Study on Grooving Corrosion at the Weld of a Low Carbon Steel Pipe Made by Electrical Resistance Welding

Kim, Yong; Lee, Bo-Young

Journal of KWJS 2004;22(5):58-64.
Published online November 12, 2004.

[연구논문] 탄소강관의 ERW 용접부 홈부식 손상에 관한 연구

A Study on Grooving Corrosion at the Weld of a Low Carbon Steel Pipe Made by Electrical Resistance Welding

Abstract

Although leakage at a low carbon steel pipe made by electrical resistance welding (ERW) was reported due to grooving corrosion, the cause for the corrosion has not yet been cleared. In order to clarify the main cause, failure analysis on the leaked pipe was carried out, followed by metallographic investigation and corrosion test for the various ERW pipe made with different welding heat input. The microstructure, particularly inclusion content, of the weldment is dependant on the welding heat input applied. For an improper low heat input, the amount of inclusion at the weld was high. High inclusion content accelerated grooving corrosion at the weld. It is therefore that welding heat input should be controlled based on the carbon content of the pipe in order to improve the corrosion resistance of the ERW pipe.