Abstract

As one of the most widely used metal materials, steel takes on an important role in deep sea and space exploration fields. However, the annual economic loss caused by steel corrosion is immeasurable. To resolve the problem, the localized pulse electrochemical machining (PECM), an efficient, fast and environment-friendly method, was introduced to fabricate microstructures on the surface of mold steel (GCr12). Results show that a super-hydrophobic surface has been obtained and its corrosion resistance has been significantly enhanced without the need to modify the surface by low surface energy solution. Thanks to the optimal working parameters (7.9 V and 2 ms) identified from the processing, the water contact angle of 161.8° was obtained. After fabrication by PECM, the surface microstructure, chemical element, and wettability were characterized and analyzed by scanning electron microscope (SEM), laser scanning confocal microscope (LSCM), EDS energy spectrometer, and optical contact angle measuring instrument, respectively. According to the experimental results, the surface honeycomb structure (micro/nano binary structure) is proven to be the main factor affecting wettability. Next, durability tests and corrosion resistance tests were carried out and the contact angle decreased by 4.4% and 6.7% respectively compared with the original contact angle, indicating that the surface after PECM has strong durability and good corrosion resistance, which can effectively solve the corrosion problem of steel. Therefore, using localized PECM technology to prepare microstructure on the surface of mold steel has a good application prospect in industry.

摘要

钢铁作为应用最广泛的金属材料之一，在深海和太空探索领域发挥着重要作用。然而，钢材腐蚀每年造成的经济损失是无法估量的。为了解决这个问题，引入了一种高效、快速且环保的局部脉冲电化学加工 (PECM) 方法在模具钢 (GCr12) 表面制造微观结构。结果表明，无需通过低表面能溶液对表面进行改性，即可获得超疏水表面，其耐腐蚀性能得到显着增强。由于从处理中确定了最佳工作参数（7.9 V 和 2 ms），获得了 161.8° 的水接触角。通过 PECM 制造后，表面微观结构、化学元素、分别采用扫描电子显微镜（SEM）、激光扫描共聚焦显微镜（LSCM）、EDS能谱仪和光学接触角测量仪对其进行表征和分析。根据实验结果，证明表面蜂窝结构（微/纳米二元结构）是影响润湿性的主要因素。接下来进行了耐久性测试和耐腐蚀测试，接触角较原来的接触角分别下降了4.4%和6.7%，表明PECM处理后的表面具有很强的耐久性和良好的耐腐蚀性能，可以有效解决腐蚀问题钢的问题。因此，采用局部PECM技术在模具钢表面制备微观结构具有良好的工业应用前景。