退火工艺对AMS 6308钢硬度及组织的影响  

Influence of annealing process on hardness and microstructure of AMS 6308 steel

作　　者：彭涛[1,2] 赵吉庆[2] 曹建春[1] 杨钢[2] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]钢铁研究总院特殊钢研究所,北京100081

出　　处：《钢铁研究学报》2016年第4期58-63,共6页Journal of Iron and Steel Research

基　　金：国家科技部863计划资助项目(2012AA03A501)

摘　　要：利用扫描电镜、透射电镜和硬度测试等方法研究了不同退火工艺对AMS 6308钢硬度及组织的影响。结果表明,提高退火温度,马氏体板条内位错密度降低,M6C的尺寸逐渐增加,硬度下降,但在750℃以上退火,进入二相区,空冷后产生二次马氏体,硬度回升。延长退火时间,马氏体板条回复逐渐充分,硬度开始下降较快,16h后组织变化不明显,M6C的含量变化不大,硬度变化也不大。退火软化程度主要受板条内位错密度的下降以及M6C的粗化控制。推荐退火温度选择700-720℃,退火时间不低于16h,720℃退火软化效果最佳。The effect of annealing process on the hardness and microstructure of AMS 6308 steel was investigated by means of SEM,TEM and hardness measurement.The results show that with elevating the annealing temperature,the dislocation density in martensite lath decreases,the size of M6 C increases and the hardness deceases.While annealing above 750℃,the hardness increases due to secondary martensite transition in dual-phase zone after air cooling.Prolonging the annealing time,the martensite lath recovers gradually,which leads to the hardness decreases sharply.The microstructure has no evident change,and the content of M6 C and the hardness change little after annealing for 16 h.The softening degree of annealing is mainly controlled by the decrease of dislocation density in martensite lath and coarsening of M6 C particles.The suggested annealing temperature is 700-720℃,annealing time should not be less than 16 h.When the steel is annealed at 720℃,it has the best annealing softening effect.

关 键 词：退火工艺 AMS 6308 退火硬度 M6C 

分 类 号：TG156.2[金属学及工艺—热处理] TG142[金属学及工艺—金属学]