Experimental Investigation on Corrosion of Cast Iron Pipes

Abstract

It is well known that corrosion is the predominant mechanism for the deterioration of cast iron pipes, leading to the reduction of pipe capacity and ultimate collapse of the pipes. In order to assess the remaining service life of corroded cast iron pipes, it is imperative to understand the mechanisms of corrosion over a long term and to develop models for pipe deterioration. Although many studies have been carried out to determine the corrosion behavior of cast iron, little research has been undertaken to understand how cast iron pipes behave over a longer time scale than hours, days, or weeks. The present paper intends to fill the gap regarding the long-term corrosion behaviour of cast iron pipes in the absence of historical data. In this paper, a comprehensive experimental program is presented in which the corrosion behaviour of three exservice pipes was thoroughly examined in three simulated service environments. It has been found in the paper that localised corrosion is the primary form of corrosion of cast iron water pipes. It has also been found that the microstructure of cast irons is a key factor that affects the corrosion behaviour of cast iron pipes. The paper concludes that long-term tests on corrosion behaviour of cast iron pipes can help develop models for corrosion-induced deterioration of the pipes for use in predicting the remaining service life of the pipes.

Resistência À Corrosão De Ligas De Ferros Fundidos Perlítico E Bainítico Em Uma Solução Sintética De Condensado a Partir Dos Gases De Combustão

“…No entanto, embora a fase ferrita apresente facilidade em formar filmes passivos, o fato de estar próxima a um material mais nobre, terá sua resistência diminuída. A fase eutética fosforosa foi a mais resistente à corrosão [13][14].…”

Niobium addition effect in molds at last cooling step on EN-GJL250 gray cast iron: Microstructural changes and electrochemical behavior

“…Many studies have been conducted to detect the mechanisms and factors responsible for degradation. Mohebbi et al [25] found that localized corrosion (pitting) is the main form of corrosion in cast iron water pipes. Mehra et al [19] investigated the variation in corrosion rate and corrosion current density of gray cast iron as a function of immersion time in various salt solutions.…”

Corrosión atmosférica acelerada en una fundición gris ASTM A48

“…Si bien es cierto que los productos de corrosión formados en la fundición gris no fueron analizados, es esperable que presente este mismo tipo de oxihidróxidos, tal como dice la literatura. [24,25], no siendo relevantes para este estudio, pues lo que se desea replicar es el comportamiento bimodal del material frente a la corrosión atmosférica marina.…”

“…El desarrollo de esta doble capa, poco antes de t a , indica la presencia de oxihidróxidos de hierro [29] que protegen al sustrato metálico del avance de la corrosión [30] que, al ralentizar la corrosión mediante una disminución en la difusión de oxígeno al sustrato, promueven las condiciones anaeróbicas para la corrosión bacteriana, producto de bacterias reductoras de sulfato (BRS). La acción de estas bacterias sería responsable del picado que aparece luego del punto de inflexión mencionado [31][32].…”