The numerical modeling and the infrared thermography principle applied to the analysis of corrosion defects in oil Conduits

Abstract

Currently the corrosion phenomenon becames a serious concern to several industries of metals and particularly of steel like nuclear, chemical and petrol industries. Such defects can occur severe economic and social damage, that's why it's so important to detect them as soon as possible to avoid those lost. The purpose of the study is to show by calculating of surface temperature the effect of corrosion defect which can exist in these conduits. To undertake the study we modelled conduit (tube) by a steel cylinder and the defect by a circular layer of rust. Dimensions of the cylinder and those of the layer of rust are taken as parameters. To see the effect of each geometrical parameter on the thermal state of the considered structure we studied the thermal state of the structure by taking this parameter like variable and all the others as constant.In fact, when a material is thermically requested (artificial excitation in the case of Laboratory measurements or natural excitation in the case of in-situ measurements), the heat diffuse in uniform way in material. The presence of a defect within the material (e.g. a crack or a rusted layer) acts like a heat insulator and idle this diffusion. It follows from there the appearance of a hotter region on the surface compared to the close one without anomaly. The study is undertaken on a cylindrical structure, as on the figure below, of geometrical parameters: external diameter d=254mm. The cylinder thickness ep =19mm, the length of tube l =1m. In order to detect the rust thermal effect on the thermal state of the steel pipe, many situations are considered. The study concerns the effect of rust thickness, rust depth and finally the number of rust layers in pipe on the surface temperature at the structure.

A Recent Progress of Steel Bar Corrosion Diagnostic Techniques in RC Structures

“…Numerous studies were carried out to assess applicability of IT technology and analyze corrosion defects existing in different structures, such as steel-concrete composite structures by Showunmi et al [70], steel-concrete composite shear walls by Matovu et al [71], concrete-filled steel tube by Xu et al [72], oil conduits by Laaidi et al [73], and organic coating layers by Jönsson et al [74]. Furthermore, many scholars proposed novel NDT methods based on induction heating and IT camera in corrosion measurement for CSB, such as an integrated system combining electromagnetic heat induction and IR by Baek et al [75] and Kwon et al [76].…”

Active Infrared Testing of Composites using 3D Computer Simulation

“…Computer simulation is widely used for investigation of thermal processes in infrared thermography (Laaidi & Belattar, 2012;El Amiri et al, 2014). The application of computer simulation to the direct problem of thermal testing in 2D was considered in Protasov (2009).…”