低合金钢中纳米碳化物相间析出行为的研究进展

An Overview of Interphase Precipitation of Nano-Carbide in Low Alloy Steels

低合金钢中的相间析出现象自发现以来,凭借其独特的相变模式及规则分布的析出产物在学术界得到了广泛的关注。近年来又凭借其强度贡献高、扩孔性能好等优点而受到了汽车行业的广泛青睐。然而由于对其背后的物理机制尚不清楚,从而对相间析出型高强钢的组织调控和性能优化提出了挑战。首先归纳了相间析出的典型形貌特征,描述了析出相的片间距、尺寸随温度的变化趋势;随后重点介绍了已有的解释相间析出现象的各类模型,并指出其存在的局限性,同时提出了在基于溶质拖曳理论的基础上可定量描述铁素体长大与碳化物析出耦合相变动力学的建模设想;最后介绍了相间析出在工业上的应用,展望了其未来在含铁素体相高强钢的强度提升及抗氢脆性能方面具有广阔的应用前景。

Since the discovery of interphase precipitation(IP)in low alloy steels,it has received extensive attention in academia due to its unique phase transformation mode and regular distribution of precipitated products.In recent years,it has been widely favored by the automotive industry with its superior strength reinforcement and excellent stretch flange formability.However,owing to its unclarified physical mechanism,a challenge is posed for the microstructure control and performance optimization of interphase precipitated steels.In this paper,the typical morphologies of IP were summarized firstly,combining with the description of the inter-sheet spacing and particle size variation with temperature.Subsequently,the emphasis was mainly placed on the introduction of various models for explaining the IP,together with the raise of their limitations.Moreover,a modeling assumption based on the solute drag theory was proposed to quantitatively describe the kinetics of coupled phase transformation between ferrite growth and carbide precipitation.Finally,the industrial application of IP was introduced.Its broad application outlook for strength enhancement and hydrogen embrittlement resistance of high-strength ferritic steel was also prospected.