Determination Of Corrosion Products Research Articles

Determination of the Chemical Composition of Corrosion Defects on the Inner Surfaces of Hollow Reinforced Concrete Structures

The paper presents the results of experimental studies on the determination of corrosion products on the surface of reinforced concrete structures. This paper also discusses methods for creating samples with artificial electro corrosion under conditions close to real operation. The paper presents the results of testing samples using laser-inducted breakdown spectrometry (LIBS) devices.

Определение химического состава на внутренних поверхностях полых железобетонных конструкций при воздействии коррозии

The paper presents the results of experimental studies on the determination of corrosion products on the surface of reinforced concrete structures. Methods for creating samples with artificial electrocorrosion under conditions close to real operation are discussed. The results of testing samples with different degrees of corrosion using laser-spark emission spectrometry (LIBS) devices are presented. The test is carried out on two different devices, a LIBS setup and a portable American-made laser analyzer LIBZ-300pe

The mechanism and identification of corrosion of steel pipes in hot water supply systems

The problem of corrosion of steel pipes in hot water supply systems is very relevant in Russia. In a number of cases, the accelerated corrosion of pipelines and fittings installed in hot water supply networks is observed. The purpose of this study is to investigate the mechanism of corrosion of steel zinc-coated and non-galvanized pipes in hot water supply systems, to analyze the causes of corrosion and to develop methods for identifying active corrosion processes occurring in water supply systems. According to literature review the microstructure and composition of the zinc coating and the methods of its application are studied. A SEM/EDS study of the structure and elemental composition of inner zinc coating on new and used steel galvanized pipes is conducted. This study shows the nonuniform distribution of zinc layer which can lead to a rapid corrosion of both the zinc layer and the metal substrate and the development of pitting corrosion. A structure and composition of corrosion sediments formed on the inner surface of pipes was studied. The different causes and factors of steel corrosion in hot water are considered and discussed. A method of corrosion identification of galvanized pipes and heat exchange equipment based on the determination of corrosion products, in particular zinc and copper, was proposed.

A Study of the Corrosion Kinetics by Coulometric Detection of Corrosion Products on a Glass Carbon Electrode

The paper reports the theoretical and experimental bases of the CDCP (Coulometric detection of corrosion products) method and examples of its application for the quantitative determination of the ionic forms of corrosion products of carbon steel, including the heat-affected corrosion areas of welding seams under strain ageing (ACWS). The experiment technique that we developed allowed us to perform selective determination of corrosion products (e.g., Fe +2 and Fe +3 in a single experiment) in the range of 1–5 μg with standard deviation s r = 0.05.

In-situ boric acid substractive process in the determinations of some transition metals in reactor coolant water by electrothermal atomic absorption spectrometry

Boric acid has a strong influence on the determination of corrosion products in reactor coolant water. Boric acid concentration can be as high as 13 g l–1. In this study we investigated the removal of boric acid from the sample matrix and the matrix effect of corrosion products. An out-of-core radiation field builds up in a pressurised water reactor because activated species (e.g., corrosion products such as Fe, Ni, Mn, Cr and Co) can re-deposit on out-of-core surfaces. Boric acid could be removed from the sample matrix in situ with a graphite furnace atomic absorption spectrometer. The subtraction process takes place in the graphite tube. Under such conditions concentrated hydrofluoric acid was used to exhaust boron from the graphite tube. The formation of low boiling boron halides, mainly boron trifluoride, constitutes fast chemical reactions. The calculated limit of quantification (p= 0.05) is 0.5 µg l–1 in all investigated elements. Cobalt, Cr, Fe, Mn and Ni could be determined within that limit. It is also possible to improve the limits of quantification of the soluble species in all the investigated elements and remove the boric acid with use of the described preconcentration method. The powerful tool multiple linear regression, in conjunction with good experimental design, can be used to determine the dependence on the sample matrix being analysed, examine the interfering elements and verify the results. The method is applied routinely to analyse the coolant at the Loviisa Nuclear Power Plant.