Corrosion of carbon steel in filling material in an urban environment

Abstract

The corrosion process of carbon steel in soil has been investigated, in particular the influence of the soil of an urban environment. A field test was carried out with test panels buried in trenches. Localized and uniform corrosion rates were evaluated after 1 and 3 years. Soil samples from points adjacent to the panels were analyzed with respect to a number of physical and chemical parameters believed to influence the corrosion process. Corrosion products were analyzed and identified. The study shows that the localized corrosion rate of soil buried constructions may be remarkably high in a filling material in comparison to other soils. The heterogeneity of the soil seems to have a greater influence on the localized corrosion rate than the chemical composition of the soil. However, the uniform corrosion rate was comparatively low in the heterogeneous filling material. Both the high alkalinity in the soil water and the groundwater, and the high total hardness of the soil water in the filling material seem to reduce the uniform corrosion rate. Corrosion rate determinations with commercial probes is also discussed. The linear polarization resistance (LPR), the electric resistance (ER) and the corrosion potential measurement techniques are compared. All probes showed a seasonal variation in corrosion rate. The measurements with commercial probes were associated with some problems, mostly a result of poor contact between the probes and the soil.

Comparative analysis for the corrosion susceptibility of Cu, Al, Al–Cu and C‐steel in soil solution

“…Over the years there have been many reports on the corrosion behaviour of metals in soil. For most part, however, these studies have been concerned with underground structures made from ferrous alloys 4–13. Much less is known about the corrosion behaviour of nonferrous metals in soils 14, 15.…”

Investigation of agar as a soil analogue for corrosion studies

“…Clay soils, especially those with high moisture content, have very small pores which restrict the movement of gases and solutes . With very high moisture content in soil the diffusion of both oxygen and solutes decreases , making conditions similar to that of solid agar with minimal oxygen. Water pipes are commonly exposed to variable moisture contents in soil as they are affected by rainfall and other climatic events .…”

“…As moisture increases in soil, oxygen diffusion decreases as oxygen and water compete for space in soil pores. The type of corrosion that occurs in soil also depends on moisture content . In moist soils, such as clays, uniform corrosion is more prevalent, whereas localised corrosion is more prevalent in dryer soils where oxygen levels are higher and more likely to form heterogeneous layers.…”

“…Corrosion in soil has previously been investigated using both solutions and soil samples . Solutions are able to simulate the chemical composition of soil, but not the physical composition.…”

Soil impacts on UK infrastructure: current and future climate

“…Higher soil moisture contents can increase corrosion rates (Ahmed, 2011;Norin and Vinka, 2003) with a seasonally fluctuating groundwater level changing the reducing-oxidising state of the soil, increasing the soil's aggressiveness to metallic, buried infrastructure (Kleiner et al, 2012).…”