Non-Destructive Coercimetry Fracture Toughness Assessment for Steel Pipelines

NON-DESTRUCTIVE COERCIMETRY FRACTURE TOUGHNESS ASSESSMENT FOR STEEL PIPELINES 3/8/2018 COMET’s main objective is to develop the first coercimetry-based fracture toughness assessment solution. Phase I will demonstrate the technical and economic feasibility of a non-destructive testing solution, based on coercivity metering, to assess material fracture toughness of steel pipelines; evaluating the correlation between coercivity and facture toughness. In the inspection and quality assurance framework, coercimetry refers to non-destructive testing of mechanical properties based on measurements of the magnetic characteristics of a metal. This technology relies on the continuous and noticeable (100-400%) increase in the magnitude of the coercivity, while the metal passes from as-delivered to its final state. As both magnetic and mechanical properties are determined by intrinsic microstructure, it is possible to formulate empirically calculated correlations between them. This technology is widely used to assess fatigue state on metal pipes (Bezlyudko et al., 2010), but has never been used to evaluate fracture toughness. Having overcome the fundamental philosophical dilemma of characterizing limit properties through non-destructive methods, coercimetry offers a solid ground base for the development of the proposed innovative solution. Following this approach, Innerspec will perform trials in order to stablish a correlation between coercivity and fracture toughness.