阳极极化下带热轧皮和生锈钢筋的可钝化性

Passivation of Rebar with Mill Scale and Stains under Anodic Polarization

关键词:  钢筋  腐蚀  钝化  轧皮

Key words:  rebar  corrosion  passivation  mill scale

摘要:

用电化学试验方法研究了有无氯离子的强碱环境中，光亮钢筋、带热轧皮未锈和生锈钢筋的阳极钝化行为.试验结果表明：在pH=125～131的强碱无氯环境中，外加50μA/cm2的阳极电流，可使光亮钢筋和带热轧皮未锈钢筋发生钝化；当[Cl-]/[OH-]≈1时，只有带热轧皮未锈钢筋显现出可钝化性；当[Cl-]/[OH-]≈5时，所有钢筋均处于活化腐蚀状态.带热轧皮生锈钢筋无论有无氯离子存在，在强碱条件下均表现为活化腐蚀，外加50μA/cm2的电流也不能使其钝化.

Abstract:

The passivation behavior of rebar with mill scale and stains, as well as the polished one under anodic polarization in strong alkali environments with and without chloride was investigated. The results show that the polished rebar and the one with mill scale could be passivated under applied anodic current of 50μA/cm2 when pH=125131 without chloride, but only the latter could remain in the passive state when [Cl-]/[OH-]≈1, and both become active when [Cl-]/[OH-]≈5. The rusted rebar stays in active corrosion state despite of existence of chloride, and the applied 50μA/cm2 anodic current is not enough to make it passive.