PH17-4 不锈钢表面电火花沉积WC–20Ni 涂层及其表征
周云龙，盛忠起，周静，张长鹏（东北大学机械工程与自动化学院，辽宁 沈阳 110819）
摘要：以WC–20Ni 作为电极，氩气作为保护气体，通过改装的HB-06 型电火花堆焊修复机在PH17-4 不锈钢基体表面沉积了WC–20Ni 涂层。以涂层厚度为指标，通过单因素试验获得最佳工艺参数为：电压125 V，频率660 Hz，电容120 μF，沉积时间3 min。采用扫描电镜、能谱仪和显微硬度计分别表征了沉积层的表面形貌、成分和显微硬度。在最佳工艺参数下，制得的沉积层组织连续、致密，与基体冶金结合且厚度均匀，约为30 μm。随着距表面距离的增大，沉积层的显微硬度逐渐降低。
文章编号：1004 – 227X (2018) 02 – 0088 – 05
Electrospark deposition of WC–20Ni coating on PH17-4 stainless steel and its characterization//ZHOU Yun-long,SHENG Zhong-qi*, ZHOU Jing, ZHANG Chang-peng
Abstract:A WC–20Ni coating was deposited on the surface of PH17-4 stainless steel by using a modified Model HB-06 electrospark overlay welding machine with WC–20Ni as electrode under Ar protection. The optimal process parameters were obtained by single-factor experiment with coating thickness as an index as follows: voltage 125 V, frequency 660 Hz, capacitance 120 μF, and deposition time 3 min. The surface morphology, composition, and microhardness of the deposited coating were characterized by scanning electron microscope, energy-dispersive spectrometer, and microhardness tester, respectively. The coating prepared under the optimal conditions is continuous, compact, metallurgically bonded to the substrate, and has a uniform thickness of ca.30 μm. The microhardness is decreased gradually along with the depth from surface in the deposited coating.
Keywords: precipitation-hardening stainless steel; tungsten carbide; nickel-based alloy; composite coating; electrospark deposition; surface hardening; microhardness
First-author’s address:College of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China