Quantitative NDT structuroscopy of cast iron castings for vehicles

Abstract

Cast irons look like 'composites' made of a steel matrix and graphite filler. The standard description of matrix and graphite structure properties, e.g., after EN 945 is not satisfactory. Physical description of its structure can be better carried out using rigidity and hardness of matrix. The expression of this description in a plane using bidimensional vector of tension strength or yield strength offers new useful relations to manufacturing metallurgy. Mathematical models among physical and mechanical properties were derived by statistical analysis. The MAT method is developed for thin-wall castings. Magnetic adaptive testing (MAT) is shortly said magnetic hysteresis NDT method exploiting large datafile created by voltage impulse induced in detection coil winded onto specimen, in dependence on immediate value of magnetic field of specimen. It is combined with another way of testing by a device for remanent magnetism measurement and an ultrasound impulse device with probes placed onto surface of the measured object, together with wall-thickness tester for thick-wall castings.