Continuous Cooling Bainite Transformation Characteristics of a Low Carbon Microalloyed Steel under the Simulated Welding Thermal Cycle Process

作     者：Xiangwei Kong Chunlin Qiu 

作者机构：School of Mechanical Engineering and AutomationNortheastern University State Key Laboratory of Rolling Technology and AutomationNortheastern University 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2013年第29卷第5期

页      面：446-450页

核心收录：

学科分类：08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 0703[理学-化学] 080201[工学-机械制造及其自动化] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：support of Shenyang Key Laboratory of Construction Project(Grant No. F12-256-1-00) Science Foundation for the Excellent Youth Scholars of Ministry of Education of China(Grant No. 90403006) 

主　　题：Low carbon microanoyed steel Bainitic ferrite Continuous cooling transformation Welding 

摘      要：Continuous cooling transformation of a low carbon microalloyed steel was investigated after it was subjected to the simulation welding thermal cycle process and the interrupted cooling test. Microstructure observation was performed by optical microscopy and transmission electron microscopy. On the basis of the dilatometric data and microstructure observation, the continuous cooling transformation （CCT） diagram was determined, which showed that the main microstructure changes from a mixture of lath martensite and bainitic ferrite to full granular bainite with the increase in the cooling time t8/5 from 10 to 600 s, accompanied with a decrease in the microhardness. The interrupted cooling test confirmed that the bainitic ferrite can form attached to grain boundaries at the beginning of transformation even if the final microstructure contains a mixture of granular bainite and bainitic ferrite.