School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;
National and Local Joint Engineering Research Center for Functional Materials Processing,Xi'an 710055,China;
School of Materials Science and Engineering,Xi'an Shiyou University,Xi'an 710065,China;
Low-carbon steel; Friction stir welding; Recrystallization; Phase transformation; Mechanical properties;