Cause analysis of surface micro-cracks on 12Mn pipeline steel Yushi Tian, Shaoyang Chu, Lijun Xu, Jun Wei, Shengtao Qiu and Rong Zhu MATEC Web Conf., 358 (2022) 01013 Published online: 19 May 2022 DOI: 10.1051/matecconf/202235801013