硅钡复合孕育剂对含硼灰铸铁组织与性能的影响

以含硼生铁配置的硼灰铸铁为对象,研究了不同质量分数的SiBa复合孕育剂对其硼元素烧损率、金相显微组织和力学性能的影响·实验结果表明:随SiBa孕育剂质量分数的增加,B的烧损率逐渐降低,由25%降至8%;而抗拉强度、硬度却随之递增,SiBa质量分数为48%时出现峰值,抗拉强度σb为282MPa,硬度为228HBS·此时,组织中石墨形态呈现A型分布,共晶团得到细化,数量由390个/cm2增加到780个/cm2;与其他几组试验结果相比,硼碳化物呈小块状且均匀分布在珠光体上·经过与标准图谱对比知,珠光体体积分数大于95%·

Effect of Silicon-Barium Compound Inoculants on Microstructure and Properties of Boron-Bearing Gray Cast Iron

Investigates how the compound inoculants of which the mass fractions of Si-Ba is formulated differently, affect the burn-off rate of boron, microstructure and mechanical properties of the B-bearing gray cast iron. The results show that the burn-off rate of boron decreases from 25% to 8% with the increasing Si-Ba content, while the tensile strength and hardness increase gradually. When the Si-Ba mass fraction is 0.48%, the peak values of both tensile strength and hardness are found, i.e., 282MPa and 228HBS, respectively. At that moment, the graphite shows morphologically the A-type distribution and the eutectic cells become finer, of which the number increases from 390 to 780 per cm~2. The boron-carbide is morphologically smaller than that without inoculants added to the cast iron and spreads over the pearlite evenly. Compared with the normal diagram, the volume fraction of pearlite is greater than 95%.