缓蚀剂添加量对Q235螺纹钢耐蚀性能的影响

目的提高螺纹钢的耐蚀性能。方法采用模拟穿水淬火冷却工艺,在加入ZnSO_4缓蚀剂的介质中对Q235螺纹钢进行淬火热处理。通过XRD测试、大气腐蚀和电化学测试(包括极化曲线和交流阻抗)等手段对不同淬火介质中Q235螺纹钢进行表征和测试。结果淬火处理后试样表面生成Fe_2O_3、Fe_3O_4和Zn(OH)_2的保护膜,当ZnSO_4缓蚀剂添加量达到120 mg/L时,Q235螺纹钢的腐蚀速度由自来水淬火状态的0.4583 g/(d·m~2)降低到0.2083 g/(d·m~2),腐蚀速度降低了54.5%;Q235螺纹钢的腐蚀电位由-0.3752 V提高到-0.2997 V,增加了20.1%;腐蚀电流由5.2482×10~(-5)A降低到1.6082×10~(-5)A,降低了69.3%;容抗谱Rr由25.58Ω增加到32.52Ω,增加了27.1%。Q235螺纹钢在模拟雨水中的极化形式为电化学极化。结论 ZnSO_4缓释剂可有效提高Q235螺纹钢的耐蚀性能。

Effect of Adding Amount of Inhibitor on Corrosion Resistance of Steel Q235

Objective To improve the properties of corrosion resistance of steel Q235. Methods The quenching heat treatments were performed with simulated water quench process on steel Q235 after adding ZnSO4 inhibitor medium. The steel Q235 was char-acterized and tested by XRD testing, atmospheric corrosion, and electrochemical tests ( including polarization curves and AC im-pedance) under different solutions. Results Fe2O3, Fe3O4 and Zn(OH)2 protective films were generated on the sample surface. When the amount of corrosion inhibitor ZnSO4 reached 120 mg/L, the corrosion rate was reduced to 0. 2083 g/(d·m2) from 0. 4583 g/(d·m2) in the water quenching. The rebar corrosion rate was reduced by 54. 5%. The corrosion potential increased from -0. 3752 V to -0. 2997 V of Q235, the corrosion potential increased by 20. 1%, the corrosion current reduced from 5. 2482× 10-5 A to 1. 6082×10-5 A, the corrosion current was reduced by 69. 3%, the capacitance spectrum value Rr increased from 25. 58Ωup to 32. 52 Ωwhich was increased by 27. 1%. The polarization of Q235 in simulated rain was the form of electrochemical polari-zation. Conclusion ZnSO4 inhibitor can effectively alleviate Q235 steel corrosion resistance.