Min SUN
金属学报(英文版)
The electrochemical corrosion behavior of 300M ultra high strength steel in chloride containing environment was investigated by potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The results show that uniform corrosion occurs on 300M steel during the electrochemical measurements because no anodic passivation phenomenon is observed on polarization curves within the measurement range. The tests also show that 300M steel is highly susceptible to chloride containing solution, which is characterized by corrosion current density increasing with the addition of chlorides, and corrosion potential shifting towards positive direction and corrosion resistance decreasing, positively suggesting that chloride ions speed up the corrosion rate of 300M steel. Meanwhile corrosion products on the 300M steel surface formed during the salt spray test are too loose and porous to effectively slow down the corrosion rate. Additionally, a schematic structure of uniform corrosion mechanism can explain that 300M steel has better property of stress corrosion cracking (SCC) resistance than stainless steels.
关键词:
300M ultra high strength steel
,
electrochemical corrosion
,
chloride
金志浩
,
葛红花
,
林薇薇
,
孟新静
,
赵玉增
腐蚀与防护
采用电化学阻抗谱(EIS)、动电位极化曲线、循环极化曲线(CP)研究了316L,2205,254SMo和2507不锈钢在含不同浓度Cl-的高炉煤气管道冷凝模拟液中的腐蚀行为.结果表明,随着Cl-浓度的增加,该四种不锈钢电极的电荷转移电阻均逐渐减小,其中2507不锈钢电极的电荷转移电阻最大,其次为254SMo不锈钢,而316L不锈钢的最小.316L不锈钢电极的极化曲线没有钝化区,腐蚀电流密度较大;254SMo和2507不锈钢电极的极化曲线存在明显的钝化区,显示较好的耐蚀性.254SMo和2507不锈钢电极的循环极化曲线中的折回段几乎沿原曲线逆向变化,显示其表面钝化膜破坏后的修复能力强;2205不锈钢回扫电流始终大于正扫电流,其钝化膜修复能力相对较差.
关键词:
高炉煤气管道
,
冷凝液
,
不锈钢
,
点蚀
,
氯离子
