电化学交流阻抗实验(electrochemical impedance spectrum，EIS)使用Gamry Reference 600型电化学工作站进行测试。腐蚀介质与极化曲线法中所使用的相同。实验测试温度仍为25℃。在100 kHz-10 mHz频率范围内，以振幅为5 mV的正弦激励电流为激发信号进行测试。 交流阻抗实验所得的实验数据采用ZSimpWin 软件进行拟合处理，继而可以得到近似的等效电路图。该数据为加入0.2mmol的 BQD为缓蚀剂的交流阻抗数据，属于BQD的交流阻抗数据组。

Electrochemical impedance spectrum (EIS) tests were performed using a Gamry Reference 600 electrochemical workstation. The corrosion medium was the same as that used in the polarization curve method. The experimental test temperature remained at 25°C. A sinusoidal excitation current with an amplitude of 5 mV was used as the excitation signal for the tests in the frequency range of 100 kHz-10 mHz. The experimental data obtained from the AC impedance experiments were fitted using ZSimpWin software, following which an approximate equivalent circuit diagram can be obtained.This data is the AC impedance data with the addition of 0.2 mmol of BQD as a corrosion inhibitor and belongs to the AC impedance data set for BQD.