In order to protect low-carbon steel parts from the erosion of corrosion medium, the soft film anti-rust oil with salt spray resistance and anti-emulsification performance was developed based on oxidized paraffin butyl ester as the film forming agent and petroleum sulfonic acid double salt as the main corrosion inhibitor. The anti-rust ability of prepared anti-rust oil was characterized by salt spray test and anti-emulsification performance test. Results showed that corrosion inhibitor barium petroleum sulfonate had a good displacement effect on water film, but had a poor effect on blocking effect of Cl-. Calcium sulfonate could effectively inhibit the corrosion effect of Cl- on metals, but it was easy to decompose in water and had poor anti-emulsification ability. By using composite corrosion inhibitor of barium petroleum sulfonate and calcium sulfonate in the formulation, the synergistic effect of the two was exerted, and the anti-rust oil with the properties of salt spray resistance and anti-emulsification performance was obtained. When the mass fraction of composite corrosion inhibitor was 12%, the optimized formula should follow the principle that the ratio of barium petroleum sulfonate to calcium sulfonate was 1∶1, or the addition amount of barium petroleum sulfonate was slightly more than that of calcium sulfonate. Adding an appropriate amount of calcium sulfonate into the formula, could not only reduce the amount of barium petroleum sulfonate so as to avoid the pollution to the environment to a certain extent, but also improve the salt spray resistance of anti-rust oil.
