冷却速度对高硼钢凝固组织及性能的影响

利用阶梯型腔金属模和砂型模拟不同的冷却速度，研究了冷却速度对高硼钢凝固组织和性能的影响。结果表明：随冷却却速度的降低，金属型试样的硼化物网孔由柱状向等轴状转变，网孔尺寸变大，硼化物的体积百分数降低，偏聚加重；砂型试样的硼化物网孔为等轴状，但尺寸和厚度最大；具有细密等轴硼化物网孔的高硼钢热处理后的冲击韧度最好，硬度适中。

Effect of Cooling Rate on Solidification Microstructure and Properties of High Boron Steel

Simulating different solidification cooling rate with step-metal mould and sand mould, the effect of solidification cooling rate on microstructure and properties of high boron steel were studied. The results show that reducing the solidification cooling rate, the meshes of boride of metal mould sample change from columnar to equal-axis, and the size of meshes increases, and the percent by volume of boride decreases, its clustering is aggravating; the meshes of sand mould sample keep isoaxial, but its size and thickness is biggest; the high boron steel with fine isoaxial boride exhibits an excellect impact toughness and a suitable hardness after heat treatment.