Determination of cleanliness different special steels comparison of different methods

One of the key properties of special steels is the cleanliness. The cleanliness is determined by the size, distribution and amount of non metallic inclusions. These inclusions are formed during the steel production process. Non metallic inclusions consist of e.g. oxygen, sulphur and different metals e.g. Al, Si, Mg, Mn, … . The size, the typ, chemical analysis, distribution are quality criteria for the steel and influences for example mechanical properties, corrosion resistance and polishability. State of the art of testing steel cleanliness is using light optical microscopes (LOM) according to international test standards. The aim of this work is the comparison of LOM-results to results derived from more time consuming, if possible 3-dimensional tests like extraction, fatigue tests and X-ray computed tomography (CT).