On formation of transverse cracks on the strand surface of peritectic steels

Based on the analysis of the extensive literature a mechanism for the formation and development of transverse cracks on the surface of slab billets of cast peritectic steels has been displayed. Hot cracking of the complex properties of cast steel - crystallization temperature range, the casting shrinkage, strength and ductility at high temperatures. Pequliarities of steel ingots peritectic solidification in the crystallizer can give rise to a number of weakened localities(?healed? hot microcracks ?hooks?, metal in the form of coarse oscillation marks), which in their turn act as nucleation transverse cracks nucleation. Analysis of the various mechanisms of the formation of the transverse surface cracks made it possible to offer a series of recommendations to reduce the probability of fracturing: a) to optimize the chemical composition of the steel in order to obtain the lowest possible temperature end δ-γ conversion in the range of existence of the single-phase austenite region existence, b) to minimize the content of harmful impurities (sulfur phosphorus, nitrogen, non-ferrous metals) in the molten steel and alloying elements, the presence of which negatively affects the mechanical properties of the steel at high temperatures; c)to provide a stable heat removal from the crust of the ingot that does not make it possible to form coarse macrogranular structure; g) to provide the conditions for the formation of large inclusions and uniform distribution in the matrix metal; d) to prevent deformation of continuous casting at temperatures with lower plastic properties