Effects of Cooling Paths on Through-Thickness Microstructure and Mechanical Properties of Heavy Gauge X80 Pipeline Steel

作     者：Xu-Dong Li Cheng-Ning Li Guo Yuan Guo-Dong Wang 

作者机构：State Key Laboratory of Rolling and AutomationNortheastern UniversityShenyang 110819China 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2017年第30卷第5期

页      面：483-492页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(No.51234002) the Fundamental Research Funds for the Central Universities(N130407001) 

主　　题：X80 pipeline steel Ultra fast cooling Cooling path Finite difference method Microstructure Mechanical properties 

摘      要：The effects of various cooling paths on uniformity of through-thickness microstructure and mechanical properties of X80 pipeline steel of 22.0 mm in thickness were studied. The finite difference method was employed to calculate the temperature field during cooling. It was confirmed by the experimental result and temperature field calculation that the optimizing process was achieved by the ultra-fast cooling with medium cooling capacity（cooling rate of ＊23 K/s）followed by ultimate cooling capacity（cooling rate of ＊50 K/s）. After optimization, the experimental steel displayed much uniform microstructure and the deviation of through-thickness hardness was controlled within 20 HV. In addition,the yield strength, tensile strength and elongation of the experimental steel were 621, 728 MPa and 21.5%, respectively,meeting the requirements of the API standard for X80 pipeline steels.