碱液输储装置用12Cr13钢的热浓碱液腐蚀行为

目前对12Cr13钢在碱液中的腐蚀行为未见研究报道.采用浸泡试验通过调整流速、碱液浓度、浸泡时间等参数研究了12Cr13钢在热浓碱液中的腐蚀行为,以明确不同因素影响碱液腐蚀的规律及碱液腐蚀机理.结果表明:试验范围内12Cr13钢静态下的腐蚀速率大于动态下的,流速增大加速了试样的腐蚀及钝化膜的修复,促进了材料表面钝化膜的生成,降低了腐蚀速率.碱液浓度低(0～20％)时12Cr13钢以钝化为主,腐蚀速率较低,碱液浓度高(＞20％)时由于过钝化溶解,使腐蚀速率显著增大;在45％碱液中12Cr13钢经历着钝化膜的生成、过钝化溶解及钝化膜的修复过程,腐蚀速率随时间增大呈先增大后降低趋势,浸泡7d出现最大腐蚀速率;动态条件下这些过程被加速,腐蚀速率减小,约是静态下的1/2.

Corrosion Behavior of 12Cr13 Steel Used in Lye Storage in Hot Alkaline Solution

By adjusting the parameters of flow velocity,concentration and time,the corrosion behavior of 12Cr13 steel in hot strong alkali solution was studied,and the effects of different factors on the laws of alkali corrosion and alkali corrosion mechanism were analyzed.Results showed that within the experimental range the corrosion rate of 12Cr13 steel in static state was larger than that in dynamic state.Increasing flow velocity accelerated the corrosion of the sample and the repairing of passive films,which promoted the formation of the superficial passive film and decreased the corrosion rate.When the concentration of alkali solution was very low (0～20％), the 12Cr13 steel was mainly passivated and the corrosion rate remained low.But when the concentration was high (＞ 20％),the corrosion rate increased significantly due to overpassivation solution.In 45％ solution,12Cr13 steel went through the process of the formation of passive film,over-passivation solution and repairing of passive film.The corrosion rate increased first but then decreased with time,reached its maximum corrosion rate when soaking for 7 d.Under dynamic conditions these processes were accelerated and the corrosion rate was reduced,about half of that under static conditions.