National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,College of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China;
State Key Laboratory of Superhard Materials,College of Physics,Jilin University,Changchun 130012,China;
Liren College of Yanshan University,Yanshan University,Qinhuangdao 066004,China;
State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China;
Twinned martensitic substructure; Twinned variant; Lath martensite; Plate martensite;
