Spark Gap Empirical Simulation During Electrical Discharge Machining of Steel 38x2h2ma

Abstract

The aim of the work is to obtain an empirical model for calculating the value of the spark gap in the electrical discharge machining of 38X2H2MA steel. Due to the fact that the discharge machining is a non-contact method, when the tool electrode is inserted into the workpiece between the end faces and the side surfaces of the tool electrode and the cavity formed, respectively, the end and side clearances are formed. The main factors affecting the size of the gaps are processing modes and material of the electrodes. The actual task is to predict the size of the spark gap when processing chromium-containing steels, depending on the modes of copy-piercing erosion processing. To obtain the empirical model, the method of factor cladding of the experiment with subsequent regression analysis was used in the work. The criterion for optimality of a plan in orthogonal central compositional planning is the orthogonality of the columns of the planning matrix. For the experiment, the following factors are selected: I -current strength (A), T on -pulse time (µs), T au -pulse fill factor (%). According to the carried out experiment and the subsequent regression analysis, a model is obtained for calculating the size of the lateral gap. On the basis of the obtained data, it becomes possible to predict the correction value when processing steel 38X2H2MA. The analysis of the model showed that the size of the gap is affected not only by the factors themselves, but also by their totality. A geometric representation of the law of variation of the lateral clearance value is presented depending on the erosion control modes. The received data allow to make adjustments of the electrode-tool dimensions in order to provide the given parameters of processing accuracy.