目的 研究 16Mn 钢在不同 S2O32?浓度的 NaAlO2 溶液中的腐蚀行为。 方法 通过盐雾腐蚀、失重法、电化学腐蚀实验以及 SEM、 EDS 等分析手段研究 16Mn 钢的腐蚀行为。 结果 S2O32?质量浓度由3 g/L 增加至 7 g/L 时，腐蚀速率从 0.4990 g/(m2·d)增大至 0.5180 g/(m2·d)，最大点蚀深度从 3.6 μm增至 4.5 μm，腐蚀电流密度由 0.648 μA/cm2 增至 5.186 μA/cm2，容抗弧半径逐渐减小。 EDS 分析可知，腐蚀产物主要由 O、 Al、 S、 Fe 四种元素组成，其中 Al、 O 元素含量较多，且随着 S2O32?浓度的增加先升高后降低。 结论 铝酸钠溶液中 S2O32?的存在会促进 16Mn 钢的腐蚀， S2O32?浓度变化对 16Mn 钢的腐蚀行为有显著影响，试样的腐蚀速率总体上随 S2O32?浓度的增加呈上升趋势。当 S2O32?质量浓度为 3 g/L 时，试样表面会生成 Al(OH)3 膜，对基体有一定的保护作用，腐蚀速率上升较缓慢；当 S2O32?质量浓度升至 4 g/L 后，氧化膜被 S2O32?穿透，腐蚀速率上升较快；但是当 S2O32?质量浓度上升到 5 g/L后，腐蚀速率增长较慢并趋于平缓。

Objective To investigate the corrosion behavior of 16Mn steel in sodium aluminate solution with different S2O32? concentrations. Methods The corrosion behavior of 16Mn steel was studied by salt spray corrosion, weight loss method, electrochemical corrosion test and analyzed by SEM, EDS. Results Corrosion rate was raised from 0.4990 g/(m2·d) to 0.5180 g/(m2·d) and the maximum pitting depth rose from 3.6 μm to 4.5 μm, when the concentration of S2O32? increased from 3 g/L to 7 g/L, while the corrosion current density rose from 0.648 μA/cm2 to 5.186 μA/cm2 and the radius of capacitive arc decreased gradually. According to EDS analysis, corrosion products were composed of four elements (O, Al, S, Fe), the contents of Al, O were higher than those of the other elements and decreased after increased first with increase of S2O32? concentration. Conclusion Existence of thiosulfate accelerated corrosion of 16Mn steel in sodium aluminate solution. Corrosion behavior of 16Mn steel was notably affected by the changing concentration of S2O32?. Corrosion rate showed a trend of escalation with the increase of S2O32? concentration. Corrosion rate increased slowly in 3 g/L S2O32? for matrix protected by Al(OH)3 coatings on the surface of sample. The oxidation coating was penetrated by S2O32? after the S2O32? concentration increased to 4 g/L, and the corrosion rate increased relatively fast. However, the corrosion rate increased slowly and tended to be stable after the concentration of S2O32? increased to 5 g/L.