Effect of temperature on the passivation behavior of steel rebar
来源期刊：International Journal of Minerals Metallurgy and Materials2014年第5期
论文作者：Shan-meng Chen Bei Cao Yin-shun Wu Ke Ma
文章页码：455 - 461
摘 要：Steel rebar normally forms an oxide or rusty skin before it is embedded into concrete and the passivation properties of this skin will be heavily influenced by temperature.To study the effect of temperature on the passivation properties of steel rebar under different surface conditions,we conducted scanning electron microscopy（SEM） observations and electrochemical measurements,such as measurements of the free corrosion potential and polarization curves of HPB235 steel rebar.These measurements identified three kinds of surfaces: polished,oxide skin,and rusty skin.Our results show that the passivation properties of all the surface types decrease with the increase of temperature.Temperature has the greatest effect on the rusty-skin rebar and least effect on the polished steel rebar,because of cracks and crevices on the mill scale on the steel rebar’s surface.The rusty-skin rebar exhibits the highest corrosion rate because crevice corrosion can accelerate the corrosion of the steel rebar,particularly at high temperature.The results also indicate that the threshold temperatures of passivation for the oxide-skin rebar and the rusty-skin rebar are 37°C and 20°C,respectively.
Shan-meng Chen，Bei Cao，Yin-shun Wu，Ke Ma
School of Materials Science and Engineering,University of Science and Technology Beijing
摘 要：Steel rebar normally forms an oxide or rusty skin before it is embedded into concrete and the passivation properties of this skin will be heavily influenced by temperature.To study the effect of temperature on the passivation properties of steel rebar under different surface conditions,we conducted scanning electron microscopy（SEM） observations and electrochemical measurements,such as measurements of the free corrosion potential and polarization curves of HPB235 steel rebar.These measurements identified three kinds of surfaces: polished,oxide skin,and rusty skin.Our results show that the passivation properties of all the surface types decrease with the increase of temperature.Temperature has the greatest effect on the rusty-skin rebar and least effect on the polished steel rebar,because of cracks and crevices on the mill scale on the steel rebar’s surface.The rusty-skin rebar exhibits the highest corrosion rate because crevice corrosion can accelerate the corrosion of the steel rebar,particularly at high temperature.The results also indicate that the threshold temperatures of passivation for the oxide-skin rebar and the rusty-skin rebar are 37°C and 20°C,respectively.
关键词：
