Study on defect of ERW weldment of carbon steel pipes

탄소강관의 ERW 용접부 손상에 관한 연구

Electrical resistance welded steel pipes showed leakage failure within 5 years usage. Microstructural analysis and hardness test were carried out, whose results gave no evidences about the reason of failure. For the analysis, 3 kinds of ERW pipes with different heat inputs were produced. Microstructural differences according to the different heat inputs were detected. Differences of the amount of inclusion in the weld line were observed. It is concluded that the difference of heat input during ERW pipe production caused the microstructural changes which resulted in the leakage failure.