A508-3钢回火过程的组织演变及动力学分析  

Microstructure Evolution of A508-3 Steel During Tempering and Kinetic Analysis

作　　者：王明敏[1] 韩利战[1] 顾剑锋[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200240

出　　处：《热处理》2013年第6期19-24,共6页Heat Treatment

摘　　要：回火对核电设备用A508-3钢的力学性能影响很大。采用扫描电镜和硬度测试研究了A508．3钢回火过程中组织的演变和性能的变化，并对经600～660℃回火的钢进行了基于硬度测量的动力学分析。回火过程中硬度的变化可以用残留奥氏体和奥氏体一马氏体的分解，贝氏体铁素体内碳化物的析出、粗化以及贝氏体铁素体的回复再结晶来解释。动力学分析表明，A508．3钢在600～660℃回火时的相变激活能约为101．4kJ／mol，与碳原子在铁素体中的扩散激活能相近。A508．3钢只有在较高温度回火时，才出现贝氏体铁素体内碳化物的大量析出和粗化，这说明该钢种具有较好的回火稳定性。The tempering sequence will have significant influence on mechanical properties of A508-3 steel for use with nuclear power equipment. The microstructure evolution and property change of A508-3 steel during tempering was investigated by SEM and hardness test, and kinetic analysis based on hardness test was performed for the steel tempered at 600 to 660℃. The hardness change of the steel during tempering will arise from decompositions of retained austenite and martensite-austensite （ M-A）, precipitation and coarsening of carbides inside bainitic ferrite, and recrystallization of bainitic ferrite. The kinetic analysis shows that the transformation activation energy of A508- 3 steel during tempering at 600 to 660 ℃ is about 101.4 kJ/mol which is close to the value of diffusion activation energy of carbon atom in ferrite. In addition, the considerable precipitation and coarsening of carbides inside the bainitic ferrite occur only in A508-3 steel tempered at higher temperatures, which indicates that the tempering resistance of A508-3 steel is excellent.

关 键 词：A508 3钢 回火 动力学分析 

分 类 号：TG156.5[金属学及工艺—热处理]