超高强度钢中复合MC型颗粒的沉淀析出及强化机制  

Strengthening Mechanism and Precipitation of Complex MC Particles in Ultra-High Strength Steel

作　　者：刘爽[1,2] 唐广波[2] 李激光[1] 李斌[1,2] 高韩锋 

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114000 [2]钢铁研究总院特殊钢研究所,北京100081 [3]西安建筑科技大学材料与矿资学院,陕西西安710055

出　　处：《钢铁》2014年第3期68-73,共6页Iron and Steel

摘　　要：利用应力弛豫法测定了一种含Nb,V,Ti和Mo多元微合金元素的超高强度钢在奥氏体中变形时的沉淀动力学(PTT)曲线,发现该钢的PTT曲线具有C形特征,最快沉淀析出温度为940℃,对应的开始析出时间约为3.6s。同时采用化学相分析及X射线小角散射法研究了该钢热轧板中析出相的成分、数量及粒度分布,用透射电镜对其析出粒子形态进行了观察。试验结果表明:该钢最终热轧板中析出相由M(C,N)和ε-Fe3C组成,其中MC型颗粒主要分布在10nm以下且均为球形或近球形,其细晶强化、沉淀强化增量分别约为207.95和195.70 MPa。Precipitation time temperature curve of a novel ultra-high strength steel, with micro-alloy element of Nb, V, Ti and Mo was tested in austenite region by the stress relaxation method. The results show that the shape of precipitation-time-temperature（PTT） is a ＂C＂ curve and the quickest precipitation juncture is about 3.6 s at 940 ℃. Composition, quantity and particle size distribution of the precipitated phase in the hot rolled plate of test steel were investigated by chemical phase analysis and small-angle X-ray scattering method; morphology of the second phase particles in the hot rolled plate was also examined by TEM. The results show that M（C,N）, ε-FeaC compose the precipitated phase in the steel, MC phase particle mainly distributed below 10nm, and all are globose or subglobose; the refinement strengthening increment is about 207.95 MPa and the precipitation strengthening increment of MC phase is about 195.70 MPa.

关 键 词：应力弛豫法 PTT 析出相 化学相分析 强化机制 

分 类 号：TG142.1[一般工业技术—材料科学与工程]