Q355B钢筋在川藏铁路地区土壤模拟液中的腐蚀行为

Corrosion Behavior of Q355B Steel Bar in Simulated Soil Solution of Sichuan-Tibet Railway Area

通过极化曲线和电化学阻抗谱测试,研究了在川藏铁路地区土壤模拟液中添加不同浓度的氯化钠、硫酸钠、硝酸钾和碳酸钠溶液和不同试验温度对Q355B碳钢腐蚀行为的影响。结果表明:当氯化钠、硫酸钠、硝酸钾和碳酸钠的添加量低于0.3%(质量分数)时,阴阳离子浓度的增大对Q355B钢腐蚀的影响较轻微;当氯化钠、硫酸钠和硝酸钾添加量达到1mol/L时,Q355B钢在添加不同溶液的模拟液中的腐蚀轻重程度依次为氯化钠、硫酸钠、硝酸钾,Q355B钢表面未见明显锈蚀和点蚀痕迹,钢表面可以维持钝化状态;在模拟液中,随着温度的升高,Q355B钢的腐蚀速率逐渐增大,70℃下Q355B钢的腐蚀速率约是15℃下的2.2倍。

The effects of different concentrations of sodium chloride, sodium sulfate, potassium nitrate and sodium carbonate solution in Sichuan-Tibet railway soil simulation solution and different test temperatures on the corrosion behavior of Q355B carbon steel were studied by polarization curves and electrochemical impedance spectroscopy. The results showed that when the addition of sodium chloride, sodium sulfate, potassium nitrate and sodium carbonate was less than 0.3%, the increase of anion and cation concentration had a slight effect on the corrosion of Q355B steel. When the addition of sodium chloride, sodium sulfate and potassium nitrate reached 1 mol/L, the corrosion severity of Q355B steel in the simulated solution with different solutions was sodium chloride, sodium sulfate and potassium nitrate in turn, and there was no obvious corrosion and pitting trace on the surface of Q355B steel, and the steel surface could maintain passivation state. In the simulated solution, the corrosion rate of Q355B steel increased gradually with the increase of temperature, and the corrosion rate of Q355B steel at 70 ℃ was about 2.2 times that at 15 ℃.