回火时间对铌钒微合金钢中析出物的影响  

Influence of tempering time on precipitates in Nb-V micro-alloyed steel

作　　者：刘庆冬[1] 刘文庆[1] 彭剑超[1] 

机构地区：[1]上海大学分析测试中心,上海200444

出　　处：《材料热处理学报》2008年第4期118-122,共5页Transactions of Materials and Heat Treatment

基　　金：上海市纳米专项(0552nm049)

摘　　要：将Nb-V微合金钢在1200℃固溶0.5h后淬火,在500℃回火不同时间,结合光学显微镜(OM)和透射电子显微镜(TEM),用三维原子探针(3DAP)研究了显微组织的变化和碳化物的析出特征。结果显示,淬火样品中V、Nb分布均匀,C由于自回火出现轻微偏聚;回火0.5h样品中有少量C-V或C-V-Nb团簇,而回火4h的样品中有大量的C-V或C-V-Nb团簇或析出相。这表明随着回火时间的延长,固溶在基体中的C、V、Nb原子首先发生偏聚,逐渐形成C-V-Nb团簇,最后形成了(Nb,V)C复合相。Three dimensional atom probe （3DAP） combined with optical microscope （OM） and transmission electron microscopy （TEM） was applied to characterize the microstructure evolution and carbides precipitation in Nb-V micro-alloyed steels quenched and tempered at 500℃ for different time after solution treatment at 1200℃ for 0.5h. The results indicate that V and Nb are almost dissolved in matrix with slight segregation of carbon in the as-quenched specimen. Fine V- and Nb-containing carbides with nano-size were detected in the specimen tempered for 0.5h. The presence of precipitates with larger size and significant increase of its number in the specimen tempered for 4h indicates that the clusters enriched with V and Nb are growing as the holding time prolonged, and （Nb, V） C compound precipitates are formed at last.

关 键 词：三维原子探针 微合金化钢 碳化物 回火 

分 类 号：TG142.1[一般工业技术—材料科学与工程]