双相钢组成相的变形行为及其影响因素  

Deformation Behavior of Constituent Phases and the Affected Factors in Dual-Phase Steel

作　　者：魏兴[1] 付立铭[2] 刘世昌[3] 王巍[4] 单爱党[2] 

机构地区：[1]六安职业技术学院机电工程系,六安237158 [2]上海交通大学材料科学与工程学院,上海200240 [3]沈阳铸造研究所,沈阳110022 [4]宝钢研究院,上海201900

出　　处：《材料研究学报》2013年第6期665-672,共8页Chinese Journal of Materials Research

摘　　要：从变形机理出发建立了双相金属材料的应力应变关系物理模型,研究了晶粒尺寸、相体积分数对材料应力应变的影响。以马氏体-铁素体双相钢为模型钢,定量计算并分析了宏观变形条件下马氏体(硬相)和铁素体(软相)的微观应力应变分配情况。结果表明,模拟的结果与实验很好吻合。体积分数及晶粒尺寸对材料中的各组成相的应力、应变分配有重要影响。随着硬相体积分数的增加,硬、软相的应力分配比逐渐降低;在较低宏观应变下硬相处于弹性变性阶段,较高的硬相体积分数具有较高应变分配比,但是随着宏观应变的增加,硬相开始塑性变形,应变比逐渐降低并最终趋于恒定,较高的硬相体积分数具有较小应变比恒定值。在体积分数一定的情况下,增大硬相的相对晶粒尺寸有助于材料的整体塑性增加,而减小硬相的相对晶粒尺寸有助于材料的整体强度提高。只有控制并调整软硬相的晶粒尺度在适当的范围内,才能更好地发挥出各组成相的潜力。A physical model has been established to predict the stress-strain relations during the de- formation of the two-phase materials, in which the effect of grain size and volume fraction of the phases on the change in strain and stress are completely considered. The predictions are good agreement with the experimental results. The micro-stress-strain partitioning between martensite （hard phase） and ferrite （soft phase） was quantitatively analyzed in the martensite-ferrite dual-phase steel. It is shown that the grain size and volume fraction greatly influence the stress-strain partitioning of the constituent phases. The stress ratio of the hard to soft phase decreases with the increase of the hard phase volume fraction. The strain ratio of the soft to hard phase increases before the plastic deformation of the hard phase starts when the relative macro-strains is applied. However with the macroscopic strain increasing, the hard phase begins to plastically deform and the strain ratio gradually reduces and eventually approaches to a constant. And the steel with relatively higher volume fraction of the hard phase has the relatively smaller constant value. In the case of a definite volume fraction, increasing the relative grain size of the hard phase contributes to the increase of the overall plasticity of the steel, while reducing the relative grain size of the hard phase helps to improve the overall strength of the steel. The optimal performance of the steel is achieved only when the grain size ratio of hard to soft phase is controlled within an appropriate range where each of constituent phases plays its most potential value.

关 键 词：金属材料 双相钢 应力应变分配 变形行为 体积分数 晶粒尺寸 

分 类 号：TG142[一般工业技术—材料科学与工程]