ZrC粒子对低碳微合金钢的强化作用

来源期刊：钢铁2010年第12期

论文作者：黄忠东 牛建平 才庆魁 黄文力

文章页码：59 - 62

关键词：低碳微合金钢； 外加微米级ZrC颗粒； 第二相粒子； 碳化物析出相； 化学相分析

Key words：low-carbon microalloy steel； added micron-grade ZrC particles； second phase particles； carbide precipitated phase； chemical phase analysis

摘    要：真空条件下,在低碳微合金钢中添加微米级ZrC颗粒,使其成为钢在热轧时奥氏体的形变核心及其形变诱导铁素体的再结晶核心以细化晶粒,获得了屈服强度为518 MPa的低碳微合金高强度钢,对钢中第二相粒子包括碳化物析出相及外加ZrC颗粒对钢的强化作用进行了讨论。采用化学相分析及X射线小角散射法研究了钢中析出相的成分、数量及粒度分布,同时用扫描电镜和透射电镜对钢中第二相粒子的形态和微观结构进行了观察,发现尺寸小于18 nm的MC析出相含量较少,未发现小于10 nm的析出相。研究结果表明:细晶强化是试验钢的主要强化方式,位错强化次之,而沉淀强化和固溶强化较小,外加ZrC颗粒在细晶强化和位错强化中产生重要作用。

Abstract: In vacuum conditions,micron-grade ZrC particles were added into a low-carbon microalloy steel as deformation center and recrystallization center of austenite and deformation-induced ferrite during hot-rolling to refine grains.A low-carbon microalloy high strength steel of yield strength 518 MPa was obtained in the laboratory.The strengthening effect of the second phase particles including carbide precipitated phase and the added ZrC particles on the steel was discussed.Composition,quantity and particle size distribution of the precipitated phase in the test steel were studied by chemical phase analysis and small-angle X-ray scattering method;morphology of the second phase particles and microstructure of the steel were also examined by SEM and TEM.It is found that there was less content of MC precipitated phase with size less than 18 nm and there was no MC precipitated phase with size less than 10 nm.The results show that refinement strengthening is the primary strengthening mode,dislocation strengthening is the second,and precipitation strengthening and solution strengthening are less.The added ZrC particles play an important role in the course of refinement strengthening and dislocation strengthening.