High-frequency eddy current conductivity spectroscopy for residual stress profiling in surface-treated nickel-base superalloys

Evaluation of Equibiaxial Compressive Stress Introduced into Austenitic Stainless Steel Using an Eddy Current Method

“…Figure 7 shows the electrical resistivity, ρ 1 , calculated using the model shown in Fig. 2(a), varying with equibiaxial compressive stress, calculated using (9) and (10). The resistivity at σ b = 0 MPa, ρ 0 MPa , is taken as a reference value, where ρ 0 MPa = 74 × 10 −8 m [13, pp.…”

“…There are a number of methods that use electromagnetic properties to evaluate the residual stress in the surface layers of metallic components, such as the potential drop technique [6], the Barkhausen method [7], and the eddy current method [5,8,9]. In the present paper, we examine the eddy current method in order to establish a rapid nondestructive test for measuring stress in the surface layers of various metallic materials, including paramagnetic and ferromagnetic materials.…”

“…Using this method, the authors previously showed that the electromagnetic properties of the surface of alloy tool steel, Japanese Industrial Standard (JIS) SKD61, peened by CP varied with processing time [10]. Also using this method, the electrical conductivity in shot-peened nickel-base superalloys was found to vary [8,9]. Blodgett and Nagy used an eddy current method to show that the electrical conductivity varied with axial stress [5].…”

Evaluation of the Residual Stress State of 42crmo4 Steel Sheets in a Production Line

“…A number of methods aimed at inspecting and quantifying residual stress levels non-destructively have been proposed; many of these are based on measurements of electromagnetic properties [3][4][5] , Barkhausen noise measurements being recognized as one of the most promising alternatives.…”

Investigation of 3D anisotropic electrical conductivity in TIG welded 5A06 Al alloy using eddy currents

“…The depth of conductivity change due to shot peening is 50-200 m from the surface, which requires high frequency electrical conductivity spectroscopy. Abu-Nabah and Nagy (2007) reported that residual stress is significantly underestimated when it is calculated from apparent eddy current conductivity (AECC) and piezoresistivity coefficient. It is observed in the present study that increase or decrease in electrical conductivity can be under predicted, if material isotropy is assumed.…”