Three dimensional mapping of corrosion pits in cast iron pipe using the remote field effect
: The remote field effect is an electromagnetic method for inspecting pipes and tubing. It has recently been commercialised as a technique for inspecting gray cast iron and ductile iron water mains. How-ever, commercial tools provide information on pits depths in the pipe and overall wall loss. Models of the mechanical behaviour of cast iron pipe also require information on pit width and length. This paper discusses remote field effect apparatus and experimental techniques used in the laboratory to produce three dimensional electromagnetic field maps. The maps shown in the paper indicate that sizing corrosion pits in three dimensions is possible using the remote field effect. Further research needs are also discussed.
The phantom exciter: high resolution measurements of RFEC slit defect interactions
In order to obtain a better understanding of defect interactions associated with the Remote Field Eddy Current technique, a new exciter/detector geometry has been used. The Phantom Exciter geometry uses a single through-wall transmission and allows high resolution measurements to be made in the region of a defect. Strong response to axial slits in nonferrous pipes due to eddy current interaction has been demonstrated. Magnetic interactions in ferrous pipe has lead to good responses to circumferential slits
Numerical Simulation of Induction Heating Process of Continuous Casting Slab
Compared with traditional blazing furnace, the Continuous Casting-Direct Rolling is an advanced manufacturing steel technology, which can reduce energy waste, decrease pollution and enhance efficiency. The characteristics of steels during induction heating are complex, the change of material properties with temperature makes exact analysis methods very difficult to implement. Therefore, a powerful computer aided numerical tool (i.e., finite difference analysis) is selected to numerically model the induction heating process in this paper. The mathematic model coupling with electromagnetic field and thermal field was established, and it was solved by finite difference method (FDM), thus the slab temperature distribution and its variation with time were obtained, and the characteristics in whole induction heating process were studied. To validate the program feasible, the results were evaluated and compared with experiment results, which showed that the simulation results are reliable and effective. The skin effect in heating process from the two results was studied and demonstrated, the temperature change caused by different parameters such as the induced power intensity and the corner radian were also presented, which indicate that the slab temperature can be heated uniformly through adjusting these parameters, thus the continuous casting slab can meet the rolling requirement.