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研究了不同输出电压下的电脉冲(ECP)处理对亚共晶铁碳合金共析组织的影响。结果表明,施加电脉冲处理产生焦耳热效应,增加了组织中原子的扩散能力和奥氏体长大的驱动力,促进了奥氏体的长大,加速了渗碳体的分解。电脉冲处理所产生的电子风力,使运动位错数量的增加。位错运动导致的位错塞积,致使渗碳体分解。渗碳体分解使奥氏体中产生浓度起伏,再加上电脉冲处理使相变势垒降低、石墨生成所需的相变驱动力减小,最终导致亚共晶铁碳合金组织中低温莱氏体的数量减少,促进石墨的生成。石墨的生成增加了铁素体的形核率和长大速率,使铁素体含量增加,珠光体含量减少。随着电脉冲输出电压的升高,ECP处理效果越加明显。
The effects of ECP at different output voltages on the eutectic iron-carbon alloy eutectoid structure were studied. The results show that Joule heating effect is generated when electric pulse is applied, which increases the diffusion ability of atoms in the structure and the driving force of austenite growth, promotes the growth of austenite and accelerates the decomposition of cementite. The electrical wind generated by the electrical pulse processing increases the number of motion dislocations. Dislocation motion caused by dislocation plugging plot, resulting in decomposition of cementite. Cementite decomposition causes concentration fluctuations in the austenite, coupled with the electrical pulse treatment to reduce the phase transition barrier, the phase change required for the formation of graphite to reduce driving force, and ultimately lead to hypoeutectic iron-carbon alloy microstructure Decreasing the number of the body, to promote the formation of graphite. The formation of graphite increases the rate of nucleation and growth of ferrite, resulting in an increase of ferrite content and a decrease of pearlite content. With the electric pulse output voltage increases, ECP treatment effect more obvious.