Detecting the tendency to chilling in series-manufactured cast-iron components using micromagnetic test procedures

During the past few decades, cast iron manufacturers have been confronted with the problem of the tendency to chilling in critical cast-iron components. The tendency to chilling refers to an undesirable occurrence of ledeburitic and cementite phases in cast iron, which normally congeals as grey cast iron. Micromagnetic test procedures like the magnetic Barkhausen noise and the analysis of the upper harmonics of the tangential magnetic field strength are suitable for the nondestructive detection of the tendency to chilling. Chilled microstructure states detected by means of micromagnetic procedures show good correspondence to metallographic results obtained at the same location. Thus, nondestructive (nd) testing methods can be used to replace destructive testing of random selected reference samples and components can be tested in-line.