References of "Verstraelen, Helen"
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See detailAssessment of corrosion resistance, material properties, and weldability of alloyed steel for ballast tanks
De Baere, Kris; Verstraelen, Helen; Willemen, Remke et al

in Journal of Marine Science & Technology (2016)

Ballast tanks are of great importance in the lifetime of modern merchant ships. Making a ballast tank less susceptible to corrosion can, therefore, prolong the useful life of a ship and, thereby, lower ... [more ▼]

Ballast tanks are of great importance in the lifetime of modern merchant ships. Making a ballast tank less susceptible to corrosion can, therefore, prolong the useful life of a ship and, thereby, lower its operational cost. An option to reinforce a ballast tank is to construct it out of a corrosion-resistant steel type. Such steel was recently produced by POSCO Ltd., South Korea. After 6 months of permanent immersion, the average corrosion rate of A and AH steel (31 samples) was 535 g m−2 year−1, while the Korean CRS was corroding with 378 g m−2 year−1. This entails a gain of 29 %. Follow-up measurements after 10, 20, and 24 months confirmed this. The results after 6 months exposure to alternating wet/dry conditions are even more explicit. Furthermore, the physical and metallurgical properties of this steel show a density of 7.646 t/m3, the elasticity modulus 209.3 GPa, the tensile strength 572 MPa, and the hardness 169HV10. Microscopically, the metal consists of equiaxed and recrystallized grains (ferrite and pearlite), with an average size of between 20 and 30 µm (ASTM E 112—12 grain size number between 7 and 8) with a few elongated pearlitic grains. The structure is banded ferrite/pearlite. On the basis of a series of energy dispersive X-ray spectrometer measurements the lower corrosion rate of the steel can be attributed to the interplay of Al, Cr, their oxides, and the corroding steel. In addition, the role of each element in the formation of oxide layers and the mechanisms contributing to the corrosion resistance are discussed. [less ▲]

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See detailStudy on alternative approaches to corrosion protection of ballast tanks using an economic model
De Baere, Kris; Verstraelen, Helen; Rigo, Philippe ULg et al

in Marine Structures (2013), 32

One of the most relevant problems in ship construction and maintenance nowadays is corrosion in ballast tanks of modern merchant vessels. On the one hand, there is a general consensus that the economic ... [more ▼]

One of the most relevant problems in ship construction and maintenance nowadays is corrosion in ballast tanks of modern merchant vessels. On the one hand, there is a general consensus that the economic lifespan of such a vessel depends, to a large degree, upon the corrosion state of its ballast tanks, while on the other hand these ballast tanks, located between the outer hull and the cargo tanks, makes routine inspection and maintenance a difficult task. Today, ship's ballast tanks are usually constructed in steel and protected with an epoxy coating backed up by sacrificial zinc anodes. Such a construction has been applied without significant alterations for many years. The objective of this economic study is to compare this construction method with some potential alternatives. The considered alternatives are: (1) an increase in structural scantlings, eliminating the necessity to replace corroded at a cost of real cargo carrying capacity of the ship, (2) application of the novel and more durable TSCF25 coating (3), the use of corrosion resistant steel in ship construction and (4) a standard PSPC15 coating combined with lifetime lasting aluminum sacrificial anodes. A cost model was used to evaluate these alternative options together with sensitivity analysis. It is concluded that the durable coating and the use of lifetime lasting aluminum anodes are bound to improve the actual basic tank concept. Corrosion resistant steel becomes attractive when the steel price becomes competitive. [less ▲]

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See detailReducing the cost of ballast tank corrosion: an economic modeling approach
DE BAERE, Kris; Verstraelen, Helen; Rigo, Philippe ULg et al

in Marine Structures (2013)

Reducing the Cost of Ballast Tank Corrosion through Innovative Ship Design: an Economic Modeling Approach

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