摘要
核电站中的690合金面临不同的酸碱性工作环境,其表面形成的钝化膜会影响自身的应力腐蚀。以pH值为1.0的H2SO4溶液和pH值为13.6的NaOH溶液模拟了690合金的工作环境,采用动电位极化、电化学阻抗和Mott-Schottky曲线测量方法研究了690合金的钝化行为及钝化膜的电化学性能。结果表明:690合金在H2SO4溶液中具有明显的钝化区间,而在NaOH溶液中则不存在,随扫描电位正移,钝化膜在H2SO4,NaOH溶液中具有明显不同的变化趋势;690合金在NaOH溶液中的阻抗模值较大;690合金在0.1V下形成的钝化膜在H2SO4溶液中的平带电位为0.6V,在NaOH溶液中的平带电位则为-0.3V。
H2SO4 solution with a pH value of 1.0 and NaOH solution with a pH value of 13.6 were used to simulate the working conditions of alloy 690.The passivation behavior of alloy 690 and electrochemical characteristics of the passivation film were investigated using potentiodynamic polarization test,electrochemical impedance spectroscopy and Mott-Schottky curve.It was found that in H2SO4 solution alloy 690 had a wide passivation region,but had no noticeable passivation region in NaOH solution.The passivation film had a higher impedance value in NaOH solution than in H2SO4 solution,and in different mediums varied with increasing potentials in different manners.Besides,the passivation film formed on the alloy surface at 0.1 V had a flat band potential of 0.6 V in H2SO4 solution,much higher than the flat band potential of the same passivation film in NaOH solution (-0.3 V).
出处
《材料保护》
CAS
CSCD
北大核心
2010年第12期4-7,共4页
Materials Protection
基金
国家自然科学基金项目(50871020)
国家科技基础条件平台建设项目(2005DKA10400)
