Atmospheric corrosion sensor based on strain measurement

Abstract

In this paper, an in situ atmospheric corrosion sensor based on strain measurement is discussed. The theoretical background for measuring the reduction in thickness of low carbon steel is also presented. Based on the theoretical considerations, a test piece and apparatus for an atmospheric corrosion sensor were designed. Furthermore, in a dry–wet cyclic accelerated exposure experiment, the measured strain indicated thinning of the test piece, although the corrosion product generated on the surface of the test piece affected the results. The atmospheric corrosion sensor would be effective for evaluating atmospheric corrosion of many types of infrastructure.

Atmospheric Corrosion Sensor Based on Strain Measurement with an Active Dummy Circuit Method in Experiment with Corrosion Products

“…According to [30,31], the strain on the compressive surface of a low-carbon (mild) steel test piece under a bending moment can be expressed by:…”

“…The test piece of the sensor is 95 mm in length, 45 mm in width, and 0.5 mm in thickness, made of low-carbon steel, has a corroded area of 1350 mm 2 , as shown in Figure 3. The ACSSM device comprises a base and cover with ρ = 430 mm, as in reference [30]. The test piece is placed in the apparatus and the edges of the test piece are fixed.…”

“…A strain measurement method using strain gauges for in situ corrosion monitoring was proposed in our previous study [30,31]. However, precise monitoring was difficult because the strain measurement method was very sensitive to temperature drift.…”

Development of Amplifier Circuit by Active-Dummy Method for Atmospheric Corrosion Monitoring in Steel Based on Strain Measurement

“…Line segment A-A is shortened upon deformation and its length is equal to (ρ − y 2 ) dθ. The strain on the A-A surface can be expressed by [35]:…”

“…These included metal loss, material characteristics of corrosion layers [34] which were analyzed using different analysis methods, such as finite element analysis (FEA) models that used two layers of the corrosion layer and test piece [7,30], microscopic analysis [5,28], and X-ray diffraction [6,25,26]. In addition to these techniques, electrochemical methods are useful because they allow in situ corrosion monitoring [35]. However, precise monitoring is difficult because electrochemical methods are very sensitive to the corrosion reactions.…”