目的 通过在生产废水中加入缓蚀剂，减少废水中氯离子的腐蚀性能，使其成为生产中的冷却水，实现节能环保。方法 采用失重法，研究废水温度对Q235钢腐蚀速率的影响，确定废水的腐蚀温度。研究L-抗坏血酸和L-半胱氨酸在废水中的最佳用量，制备成复配缓蚀剂，研究复配缓蚀剂膜形成的最佳时间。用塔菲尔曲线、阳极极化曲线及交流阻抗法，研究存在与不存在复配缓蚀剂膜的Q235钢的自腐蚀电流密度、极化腐蚀电流密度和极化阻抗。用SEM研究复配缓蚀剂膜腐蚀前后的形貌变化。结果 在60 ℃的生产废水中，L-抗坏血酸的最佳用量为165 mg/L，L-半胱氨酸的最佳用量为18 mg/L，复配缓蚀剂膜的形成时间为24 h。无缓蚀剂膜时，Q235钢的自腐蚀电流密度为4.918×10?5 A/cm2；在500 mV过电位下，极化腐蚀电流密度为1.667×10?2 A/cm2，极化阻抗为529 Ω?cm2。形成复配缓蚀剂膜的Q235钢片的自腐蚀电流密度为3.433×10?7 A/cm2，极化腐蚀电流密度为4.132×10?6 A/cm2，极化阻抗很大。复配缓蚀剂的缓蚀率为80.15%，明显高于单一缓蚀剂。SEM测试表明，在过电位为500 mV时，无缓蚀剂膜的Q235钢腐蚀十分严重，有复配缓蚀剂膜的Q235钢几乎不腐蚀。结论 在PVC热稳定剂生产废水中加入适量的缓蚀剂，具有较好的缓蚀性能，基本满足作为冷却水的要求。

The work aims to reduce corrosion resistance of Cl ions in wastewater by adding corrosion inhibitor in industrial wastewater, so as to make the wastewater cooling water in production and realize energy conservation and environmental protection. The effects of wastewater temperature on corrosion rate of Q235 steel were studied in weight loss method to determine corrosion temperature of wastewater. Optimal volume of L-ascorbic acid and L-cysteine in wastewater was studied, a compound corrosion inhibitor was prepared, and optimal time for the formation of compound corrosion inhibitor film was investigated. Self-corrosion current density, polarization corrosion current density and polarization impedance of Q235 steel with and without complex corrosion inhibitor film was studied in the methods of Tafel curve, anodic polarization curve and AC impedance, respectively. Morphological changes of the film before and after corrosion were studied with SEM. The optimal volume of L-ascorbic acid was 165 mg/L and L-cysteine 18 mg/L in the industrial wastewater at 60 ℃. Formation time of the compound corrosion inhibitor film was 24 h. The self-corrosion current density of Q235 steel without corrosion inhibitor film was 4.918?10?5 A/cm2. The polarization corrosion current density was 1.667?10?2 A/cm2 and polarization impedance was 529 Ω?cm2 at overpotential of 500 mV. The self-corrosion current density of Q235 sheet steel with complex corrosion inhibitor film was 3.433?10?7 A/cm2, polarization corrosion current density was 4.132?10?6 A/cm2, and the polarization impedance was high. Inhibition rate of the compound corrosion inhibitor was 80.15%, significantly higher than that of a single inhibitor. SEM test showed that Q235 steel without corrosion inhibitor film was severely corroded and that with corrosion inhibitor film was barely corroded at overpotential of 500 mV. Corrosion resistance of the industrial wastewater of PVC heat stabilizer is improved by adding moderate amount of corrosion inhibitor, the wastewater basically meets the requirement for cooling water.