摘要：In this paper, the corrosion inhibition perfor-mance of [C16DMIM] [PF6] ionic liquid on mild steel in 1M H2SO environment and the corrosion in-hibition performance and mechanism of[C16DMIM][PF6] compounded with KI, thiourea and formalde-hyde, respectively, were investigated based on seri-ous corrosion hazards of metal pickling. The inhibi-tion ability of [C16DMIM] [PF6] was evaluated by static weight loss method, electrochemical corrosion testing and microscopic morphological analysis, while the synergistic effect of the ionic liquid com-pounded with KI, thiourea and formaldehyde was explored by experiments and quantum chemical cal-culations(QC). The static weight loss results showed that the addition of 20 mg/L [C16DMIM] PF6]could achieve 80.1% inhibition efficiency, and the combination of 20 mg/L KI could achieve 95.9% ef-ficiency and maintain 94.1% efficiency after7h.The electrochemical results showed that both [C16DMIM] [PFo] and the compounded corrosion inhibitor showed a mixed inhibition mode, and the impedance test revealed that the corrosion inhibitor formed a double electric layer to reduce corrosion through the charge transfer process. Scanning elec-tron microscopy(SEM) observed that the surface of the mild steel was smooth and the corrosion depth was reduced after the effect of the compound corro-sion inhibitor. The synergistic effect of ILs and KI is optimal. The synergistic mechanism is that I prefer-entially adsorbs on the surface to form a bridge and thus attracts the protonated [C16DMIM] [PF6] for adsorption, which in turn enhances the strength of the adsorbed film and makes the protective film denser.
