钻井扶正器硬质合金镶块碎体的电化学溶取

Electrochemical machining for removing broken hard alloy inserts in drilling centralizers

采用电化学溶取法清除钻井扶正器硬质合金镶块碎体是一种简单易行、省事省力的方法。通过正交优化实验，优选出采用双极性脉冲电流，以15％NaCl＋20％NaKC4H4O6＋5％添加剂A＋5％添加剂B弱碱性电解液为基础的加工工艺参数。实验结果表明，采用优化工艺，清除1个硬质合金镶块碎体仅需3－5min，生产效率比手工抠取方法提高7倍，并可获得较高的加工精度（0．13mm）和较低的表面粗糙度值（0．8μm），材料去除率可达19．2mm3／min。采用这项工艺，每套装置每年可创经济效益近23万元。

Electrochemical machining (ECM) is a simple and practicable means for removing broken hard alloy inserts indrilling centralizers. The parameters for this technology are optimized by lab tests, in which electrolyte of 15% NaCl +20% NaKC4H4O6 + 5% additive A + 5% additive B is adopted. By using the optimum ECM technology, it takes only3 ~ 5 minutes to remove a broken insert, and high machining accuracy and minor surface toughness can be achieved. Thetechnology can bring about remarkable financial profits.