酸性介质中N,N-二苯基硫脲和硫脲对A3钢的缓蚀作用对比研究

Contrast Study on the Inhibitive Effect of N,N-diphenyl Thiourea and Thiourea on the Corrosion of A3 Steel in Acid Medium

采用动电位扫描极化曲线、交流阻抗法和量子化学法,研究了N,N-二苯基硫脲(DPH-TU)在5%H2SO4介质中对A3钢的缓蚀作用及缓蚀机理,计算出了相应吸附过程的热力学数据,并与硫脲进行了对比。研究表明:N,N-二苯基硫脲是一种缓蚀效果显著的混合型缓蚀剂,它在A3钢表面发生化学吸附,吸附过程为放热过程,吸附行为服从El-Awady动力学模型,其缓蚀效果明显优于硫脲。

The inhibitive behavior and mechanism of N,N-diphenyl thiourea （DPH-TU） on the corrosion of A3 steel in 5 % H2 SO, medium were studied using polarizationcurves measurements, electrochemical impedance spectroscopy （EIS） and quantum chemistry methods in order to investigate the inhibitive effect of DPH TU in H2SO4 solution and providing important theoretical reference to the actual production as corrosion inhibitor. The results show that DPH-TU is an effective and mixing type inhibitor. It is suggested that the adsorption of DPH-TU on A3 mild steel be chemosorption and exothermic reaction. The corresponding thermodynamic parameters of the adsorption process for DPH-TU are calculated according to the El Awady kinetic model. Compared with the thiourea, the inhibition effect of DPH-TU is superior to thiourea.