摘要
将Nb-V微合金钢在1200℃固溶0.5h后淬火,在不同温度回火4h,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)研究了淬火与回火样品中碳化物的特征.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;450、500、550和600℃回火样品中存在大小和数量不同的V和Nb的碳化物,其中550℃回火样品中数量最高,对应着二次硬化的硬度峰值;650℃回火样品中数量明显减少,与硬度下降对应.
3D atom probe combined with OM and TEM was applied to characterize the carbides precipitation and microstructure evolution in Nb-V microalloyed steel plates quenched after solution treatment at 1200℃ for 0.5 h and tempered at 500---600℃ for 4 h. The results indicated that vanadium and niobium were homogeneously dissolved in matrix with slight segregation of carbon in the as-quenched specimen. V and Nb containing carbides with different sizes and number densities were detected in the specimens tempered at 450, 500, 550 and 600 ℃, and among which the fine carbides precipitated at 550℃ had the highest number density, contributing to a maximal secondary hardening effect, while the amount of the fine carbides reduced significantly at 650 ℃, corresponding to the decrease of the hardness.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第7期786-790,共5页
Acta Metallurgica Sinica
基金
上海市纳米专项项目0552nm049
上海市重点学科建设资助项目T0101资助~~
关键词
三维原子探针
微合金钢
碳化物
回火组织
3D atom probe, microalloyed steel, carbide, tempered microstructure
