The precipitation kinetics of TiC and VC during high-temperature tempering of low-carbon martensitic steels was studied by means of hardness measurement and theoretical analysis. The precipitation–temperature–time diagram, which was determined through the hardness versus tempering time curves, shows that the precipitation rate of TiC is more rapid than that of VC at 600 °C or above, while they are almost the same at 550 °C. The number density of TiC precipitates is larger than that of VC precipitates, thus leading to a larger secondary hardening effect. An analytical model to describe the precipitation kinetics of microalloying carbides during tempering of martensitic steel was presented. Using this model, the difference of precipitation kinetics between TiC and VC can be well explained, in terms of the shape and relative position of kinetics curves and the nose temperature.

中文翻译：

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揭示低碳回火马氏体钢中 TiC 和 VC 析出动力学的差异

通过硬度测量和理论分析，研究了低碳马氏体钢高温回火过程中TiC和VC的析出动力学。通过硬度与回火时间曲线确定的析出-温度-时间图表明，在 600 °C 或更高温度时，TiC 的析出速率比 VC 更快，而在 550 °C 时它们几乎相同. TiC析出物的数量密度大于VC析出物的数量密度，从而导致更大的二次硬化效应。提出了描述马氏体钢回火过程中微合金化碳化物析出动力学的分析模型。使用该模型，可以很好地解释 TiC 和 VC 的析出动力学差异，