为了减缓甲醇回收系统的腐蚀，通过失重法对20钢在含甲醇模拟污水中的缓蚀剂进行了筛选及优化，并通过极化曲线法研究了缓蚀剂的缓蚀性能；通过能谱（EDS）分析和阻垢性能试验研究了缓蚀剂的阻垢性能。结果表明：聚磷酸钠、有机膦A和ZnCl₂以质量比2：1：2复配，且该复合缓蚀剂用量为90 mg/L时，缓蚀性能最好，缓蚀率达到95.47%；该复合缓蚀剂是抑制电极阳极反应为主的混合型缓蚀剂；含磷缓蚀剂在20钢表面形成膜从而有效地阻挡了腐蚀介质对基体的腐蚀，且该复合缓蚀剂具有较好的阻垢作用，阻垢率达83.33%.

Corrosion inhibitors of 20 steel in the simulated wastewater containing methanol were selected and optimized by weight loss method in order to slow down the corrosion rate of methanol recycle system, and their corrosion inhibition was studied by polarization curve method. The scale inhibition was investigated through energy dispersive spectroscopy (EDS) and scale inhibition testing. The results show that when the mass ratio of sodium tripolyphosphate to organic phosphorus A and to zinc chloride was 2:1:2, and the adding amount of compound corrosion inhibitor was 90 mg/L, the compound corrosion inhibitor showed the best inhibition with inhibition efficiency of 95.47%. The compound inhibitor was a mixed inhibitor which inhibited anodic reaction mainly. A protective film was formed on the surface of 20 steel from inhibitors containing phosphorus and resisted corrosive medium to corrode the substrate. The compound inhibitor also presented good scale inhibition, whose scale inhibition efficiency was 83.33%.