Microstructural Evolution and Properties of a High Strength Steel with Different Direct Quenching Processes

作     者：Feng LU Chao WANG Long L Zhao-dong WANG Guo-dong WANG Raja Devesh Kumar MISRA 

作者机构：State Key Laboratory of Rolling and AutomationNortheastern University Department of Metallurgical and Materials EngineeringUniversity of Texas at El Paso 

出 版 物：《Journal of Iron and Steel Research International》 (J. Iron Steel Res. Int.)

年 卷 期：2015年第22卷第4期

页      面：344-351页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 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] 080201[工学-机械制造及其自动化] 

基　　金：Item Sponsored by National Natural Science Foundation of China(51234002) 

主　　题：high strength steel direct quenching slow cooling carbon partitioning precipitation 

摘      要：A high strength low alloy steel with low carbon equivalent was selected for simulating online direct quench- ing and coiling （DQ-C） process. The influence of stop quenching temperature on mechanical properties and micro- structures was studied and compared with normal direct quenching and tempering （DQ-T） process. The study con- firmed that required mechanical properties were obtained for both the processes. Properties of the experimental steel with DQ-C process could reach the same level as that of DQ-T process in general. In the DQ-C process, strength de- creased with increase in stop quenching temperature. Martensite was obtained and experienced an aging process at stop quenching temperature below Mi. On fast cooling below Mi, martensite was partially transformed and carbon partitioning occurred during slow cooling. The reduction in solid solution carbon and increased amount of retained austenite led to lower strength compared with the DQ-T process. DQ-C process was more favorable for microalloy carbide precipitation. However, impact toughness under different cooling conditions was adequate because of low car- bon equivalent and refined microstructure.