渐变式电压、电流电渣重熔工艺分析

为了研究渐变式电压、电流电渣重熔工艺对铸锭组织性能的影响,以45号钢为试验原料,采用低倍腐蚀、光学显微镜(OM)、扫描电子显微镜(SEM)、拉伸力学试验等手段,对比了传统电渣工艺与参数渐变工艺对铸锭凝固组织及性能的差异。结果发现,重熔阶段先逐步降低过程电压,待电压降到一定值后,再逐步降低电流,直至结束熔炼,可以减小铸锭柱状晶组织与铸锭轴线的夹角,使铸锭组织倾向于定向凝固,提高铸锭轴线方向的抗拉强度。此外,通过该工艺获得的凝固组织中铁素体量降低,珠光体中层片结构得到明显细化。

Study on gradual voltage and current electroslag remelting process

In order to study the influence of gradual voltage and current electroslag remelting(ESR) process on the structure and properties of ingots, No.45 steel was used as the experimental material to obtain the differences of solidification structure and properties on the traditional ESR process and parameter gradual changing process. The samples were analyzed by means of low power corrosion, optical microscope(OM), scanning electron microscope(SEM) and tensile mechanics test. It was found that the voltage was gradually reduced to a certain value and then the current was gradually reduced until the melting was finished. This process can reduce the angle between the ingot columnar crystal structure and the axis of the ingot, make the solidification structure be more inclined to directional solidification structure and improve the tensile strength of ingot in the axial direction. In addition, the amount of ferrite in the solidification structure decreased and the structure of pearlite middle lamellae was refined obviously.