中文摘要：

在高硼中碳合金的凝固过程中施加电脉冲，研究了电脉冲频率对其凝固组织及力学性能的影响。结果表明，电脉冲对高硼中碳合金凝固组织中的共晶莱氏体和硬质相数量和形态有明显影响，从而影响合金的力学性能。在经过电脉冲处理的高硼中碳合金凝固组织中共晶莱氏体消失，硼碳化物硬质相产生断网现象，使材料硬度和冲击韧性得到提高。随着电脉冲频率提高硬质相断网现象更加明显，材料硬度和冲击韧性提高。电脉冲对高硼中碳合金凝固组织及其力学性能的影响，是焦耳热效应、电磁力效应及电迁移效应共同作用的结果。

英文摘要：

The influence of electric pulse frequency on the solidification microstructure and mechani- cal properties of high-boron middle-carbon alloy has been investigated. The experimental results show that electric pulse has obvious influence on the eutectic ledeburite and hard phase of the steel, lead to the change of mechanical properties. The ledeburite in the steel disappeared and the continuious boron carbide hard phase was broken into small particle, which lead to the improve of hardness and impact toughness of high-boron middle-carbon alloy. Along with the frequency increasing, the influence on the solidification microstructure and properties of the steel is more obvious. The influence is the results of the joule heating, the electromigration effect and electric magnetic effect.