Research on Precipitate Behavior during Holding Process of X80 Pipeline Steel Tao Niu, Chenggang An, Yongwen Jiang, Xinlang Wu, Caixia Zhang, Chen Yu and Xiaoli Dai MATEC Web Conf., 67 (2016) 05006 Published online: 29 July 2016 DOI: 10.1051/matecconf/20166705006