The method of magnetic coercimetry and its application to assess the residual life of lifting equipment

Material fatigue damage accumulation is recognized as one of the least inspectable and controllable operational damage mechanisms of crane structures. The scope method measures electro-magnetic properties of steels being in service, to assess their relative changes induced by the fatigue damage accompanying microstructural effects. The authors’ theoretical and experimental research suggested that the most relevant magnetic parameter to measure is the coercive force Hc, which is a characteristic of ferritic steels’ magnetization-demagnetization hysteresis loop. The authors proposed and developed a correction factor to normalize changes in H c for various carbon steel thicknesses in the practical range from 5mm to 20mm, and drawn the coercive force nomograms which quantify the extent of damage for typical structural steels used in cranes. This research provided a scientifically justified basis for structures remnant resource assessments. Application of the Coercimetric method contributes into the risk control and promotes industrial safety in lifting equipment operations. The method itself can be practically useful for resolving integrity management challenges in a wide range of industries.