304和316L不锈钢的高温电化学腐蚀行为

Electrochemical Investigation of Corrosion Behavior of 304 and 316L Stainless Steels in High-Temperature Water

通过模拟压水堆一回路水环境,研究了溶液温度和溶氧量(DO)对304和316L不锈钢高温电化学腐蚀行为的影响.结果表明:随着溶液温度升高,在304和316L不锈钢表面所形成的氧化膜的保护性能降低;随着DO升高,304和316L不锈钢的自腐蚀电位升高,自腐蚀电流密度降低,钝化区缩小;304和316L不锈钢表面形成了双层氧化膜,外层氧化膜颗粒尺寸和颗粒间隙随着温度的升高而增大,随着DO增加而减小;在所用实验条件下,316L不锈钢表现出比304更优异的抗腐蚀性能.

The effects of temperature and dissolved oxygen（DO）on electrochemical behaviors and the oxide films formed on type 304 and 316Lstainless steels in primary water in simulated pressured water reactor（PWR）were investigated by means of potentiodynamic polarization measurements,scanning electron microscope（SEM）observation and energy dispersive X-ray spectrum（EDS）.The results revealled that the passivity of the oxide films degraded with increasing solution temperature.The corrosion potential（Ecorr）shifted to positive direction while corrosion current density（Jcorr）decreased significantly with the increase of DO.The oxide films formed on 304 and 316Lstainless steels showed a double-layer characteristic,and the size of oxide particles and the space between oxide particles on outer layer increased with increasing temperature but decreased with increasing DO.The type 316 Lstainless steels exhibited superior corrosion resistant characteristics than 304 SS in all investigated conditions.