Department of Materials Forming and Control Engineering, Anhui University of Technology, Ma'anshan 243002, China;
Provincial Key Laboratory of Metals and Processing, Ma'anshan 243002, China;
Steel Tube & Pipe Company of Bao Steel Co. Ltd., Shanghai 200941, China;
Department of Metallurgy and Materials Science, Changwon National University, Changwon 641-773, Korea;