低活化钢中MX相析出行为研究  

Investigation on Precipitation Behaviors of MX Phase in Reduced Activation Steels

作　　者：施正[1] 张弛[1] 夏志新[1] 张玉朵[1] 杨志刚[1] 丁雅莉[2] 

机构地区：[1]清华大学材料科学与工程系先进材料教育部重点实验室,北京100084 [2]钢铁研究总院结构材料研究所,北京100081

出　　处：《原子能科学技术》2011年第2期200-205,共6页Atomic Energy Science and Technology

基　　金：国家重点基础研究发展计划资助项目(2010CB731600);国家自然科学基金资助项目(50871059;51071090)

摘　　要：研究了不同合金成分的低活化钢中MX（M=Ta,X=C、N）相在750℃下保温不同时间的转变行为,低活化钢中Ta的稳定析出相为TaC。经1 050℃固溶处理后,平均尺寸约150 nm的未溶TaC颗粒钉扎原奥氏体晶界和板条束界,阻碍晶界和板条束界的迁移。经750℃回火后,在晶界和晶内析出尺寸为15~45 nm细小弥散的TaC相。低活化马氏体钢回火过程中回溶的Ta原子在随后的析出过程中在新位置形核,而不是在原TaC颗粒上形核长大,导致低活化马氏体钢中TaC有较小的长大速率。在回火初期,TaC在基体中共格析出,在长时间回火过程中,TaC以特定的原子面（200）TaC、（111）TaC析出、长大。The evolution of MX（M=Ta;X=C,N） phase in modeling steel during tempering at 750 ℃ was studied.The results indicate that TaC can be formed in reduced activation steels.TaC particles in two different scales were identified.The larger undissolved TaC particles exert strong pinning force on migrating of martensitic packet and prior austenite grain boundaries after austenitizing.The small TaC particles formed during tempering have an average diameter from 15 to 45 nm with the increase of tempeing time.The re-dissolution of the precipitated TaC particles during tempering can lead to the precipitating of new particles without causing the coarsening of the pre-existing particles,as a result,the coarsening rate of MX particles slows down.TaC particles grow along the particular atoms plane（200）TaC,（111）TaC during precipitation and coarsening.

关 键 词：低活化钢 碳化钽 回溶 回火 

分 类 号：TG146.1[一般工业技术—材料科学与工程]