Corrosion characteristics of cast iron exposed in manholes for sewer

DOI Web Site

Bibliographic Information

Other Title
  • 下水道管渠内に暴露された鋳鉄の腐食特性
  • ゲスイドウカンキョナイ ニ バクロ サレタ チュウテツ ノ フショク トクセイ

Search this article

Abstract

<p>　Manhole covers made of cast iron corrode in sewer environment. In this study, the corrosion characteristics of cast iron were studied in 12 manholes where the mean annual concentrations of hydrogen sulfide were 0 to 70 ppm. The corrosion rates of specimens made of cast iron were calculated from weight loss for four-month, one-year, two-year and three-year exposure tests. The values of pH of water droplets condensed in these manholes were measured. The weight loss is linear function of time, therefore the corrosion rates of the specimens are constant. In seawater, soil and atmospheric environments the corrosion rates of iron-based materials decrease sharply within three years, because corrosion products tend to be protective. Acidic dew condensation water in manholes makes rust products porous and loose. Cast iron is not covered with protective corrosion products, accordingly the corrosion rates of cast iron dose not decrease with time.</p>

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top