In the high-alloy, ferritic - austenitic (duplex) stainless steels high tendency to cracking, mainly hot-is induced by micro segregation
processes and change of crystallization mechanism in its final stage. The article is a continuation of the problems presented in earlier
papers [1 - 4]. In the range of high temperature cracking appear one mechanism a decohesion - intergranular however, depending on the
chemical composition of the steel, various structural factors decide of the occurrence of hot cracking. The low-carbon and low-alloy cast
steel casting hot cracking cause are type II sulphide, in high carbon tool cast steel secondary cementite mesh and / or ledeburite segregated
at the grain solidified grains boundaries, in the case of Hadfield steel phosphorus - carbide eutectic, which carrier is iron-manganese and
low solubility of phosphorus in high manganese matrix. In duplex cast steel the additional factor increasing the risk of cracking it is very
"rich" chemical composition and related with it processes of precipitation of many secondary phases.