钒对耐火钢显微组织及高温性能的影响

 通常采用控轧控冷方式生产耐火钢Mo-Nb复合合金化。采用电子显微镜、相分析和三维原子探针等方法，研究了不同热轧工艺条件下钒对含钒耐火钢的室温和600 ℃拉伸性能的影响，探讨了微观组织与力学性能之间的关系。结果表明，添加钒后能形成细小弥散分布的析出物，配合控制贝氏体比例后能有效地提高室温和高温力学性能；钒在热轧态耐火钢中主要固溶于先共析铁素体内，再加热至600 ℃时热轧态被“隐藏”的钒存在明显的析出，进一步提高了含钒耐火钢的高温性能。

Effect of vanadium on microstructure and high temperature properties of fire-resistant steels

The combined addition of molybdenum and niobium is usually applied to produce fire-resistant steels with ap-propriate controlled rolling and controlled cooling. Methods,such as electron microscope,phase analysis,tensile test, three dimension atom probe and so on were used to investigate the effect of vanadium on the microstructure and tensile properties at both room temperature and high temperature up to 600℃for every kinds of hot-rolling process in vanadi-um-containing fire-resistant weathering steels. The relationship between the microstructure and the mechanical proper-ties was analyzed. It has been found that the amount of vanadium precipitates would be finer and denser as the amount of adding vanadium rised. The effect of vanadium depends on the control of the bainite fraction in the microstructure, which is essential for tested steels to obtain good high-temperature yield strength and high yield strength ratio (YS ratio). Vanadium exists mainly in the proeutectoid ferrite in the hot rolled fire resistant steel,the"hidden"vanadium precipitat-ed from the base microstructure when the temperature was elevated to 600 ℃,the high temperature properties of the test samples would be improved simultaneously.