Corrosion-induced damage

A. Corrosion-induced damage has inevitably arisen since man learnt to extract metals. The spheres and scale of metal assimilation have widened continuously and the problem of losses from corrosion have been aggravated and become more acute. Machines and metal constructions today constitute the most valuable part of basic production assets in the world. By the end of the 20th century economic losses from corrosion had reached a magnitude commensurate with worldwide investments into the development of the main branches of industry. Experts estimate annual damage by corrosion of up to... 

FIGURE 6.24 Corrosion-induced damage tolerance of OPC concrete and DFRCC material. (From Maalej, M. et al, Journal of Advanced Concrete Technology, 1(3) 307-316, 2003. With permission from JCI.)... 

Superior corrosion-induced damage resistance of HPFRCC is also evident in terms of negligible to no corrosion-indntted (aacks and their small width. 

In the period 2002-2003 we focused on performing phase analyses of corrosion-induced damage to feed water pipelines in SGI6 near the heterogeneous weld. Visual inspections were done, and original in situ specimens were scraped off. The conclusions from the visual inspections (performed on 19 and 29 April 2002 at SG16) were as follows. 

Additional goals become relevant, in particular with respect to the protection of larger properties not subjected to direct fire influences, such as corrosion induced by the fire effluents. Hereby, the long-term corrosion damage to the building and to equipment (industrial machinery as well as electrical and electronic installations) is of great interest. 

In a damaged (scribed) corrosion protection system, the wet adhesion of a coating becomes the most important factor because both liquid water and corrosive species attack the interface. A water-delaminated coating layer does not provide any corrosion protection. Thus, water-insensitive adhesion of a coating to a substrate is a mandatory requirement for the prevention of corrosion-induced delamination. 

It is generally difficult to eliminate all the droplets leaving with the air flow so that in induced draught designs, these droplets are likely to enter the fan system with the possibility of erosion and corrosion and damage to the fan. 

Mechanochemical wear is an intricate process in which corrosive damage and mechanical wear are interrelated [1,2]. The role of corrosive and mechanical factors in corrosion-induced wear of metals in electrodes is estimated in different ways. Some authors consider this process as purely corrosive, others... 

Due to their high sensitivity to strain, temperature variation, vibration, and acoustic waves, embedded extrinsic Fabry-Perot interferometric optical fiber sensors have been developed to detect delamination, based on changes in the acoustic properties of the materials before and after delamination [41]. Impact events and corrosion cracking generate ultrasonic waves, which can be characterized using elliptical core fiber sensors [40]. The in-line Fabry-Perot interferometer seems well suited for the local detection of shear waves and the characterization of impact-induced damage. 

To provide longer service life to the concrete decks of the order of 75-120 years without the need to repair corrosion-induced concrete damage, a number of solid and clad corrosion-resistant 304 and 316 stainless steel rebars have been developed. Both alloys provide excellent corrosion protection but at higher cost. Type 316 stainless rebar requires more detailed studies. 

Liu ZY et al (2008) Characterization of carbon corrosion-induced structural damage of PEM fuel cell cathode electrodes caused by local fuel starvation. J Electrochem Soc 155(10) B979-B984... 

Besides corrosion-induced rebar damage, there are three other commonly cited forms of concrete degradation, namely, alkali-aggregate reaction, freeze-thaw damage, and sulfate attack. 

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