Castings

Abstract

Here, flaw detection almost exclusively concerns manufacturing defects such as shrinkage cavities and blow holes (the former with coarse, jagged, the latter with smooth surface, in smaller dimensions also pores and porosity), furthermore inclusions (usually sand or slag) and cracks (caused by internal stresses during cooling while already solidified). Pure segregations are detected very rarely and then only by indirect means. If, in exceptional cases, a casting has to be checked for fatigue cracks, the testing technique, as in the case of forgings, mainly depends on the stresses because they determine the possible position of the flaw.