Analysis of Leakage Cause of L415M Spiral Submerged Arc Welding PipeYan Xu, Yinglai Liu, Xianghui Nie, Zhenjun Feng, Liang Li and Fengping YangE3S Web Conf., 329 (2021) 01071DOI: https://doi.org/10.1051/e3sconf/202132901071