Study of Conditions for Improving Chemical and Structural Homogeneity of Ferritic Class Hot-Rolled Steels

Redistribution of carbon and other elements, and formation of the structure, composition, and properties of low-carbon Nb, Nb–Ti, Nb–V, Nb–V–Mo and Ti–Mo microalloyed steels during hot rolling is studied using metal of five laboratory melts. It is established that by selecting the temperature for the beginning of rolling in the finishing group of stands according to steel composition (microalloying system) it is possible to achieve a significant improvement in the homogeneity of the composition, structure, and set of rolled product properties. Therefore, it is demonstrated by experiment that chemical and structural heterogeneity of metal formed in the billet casting stage may be largely eliminated during hot rolling on the basis of controlling carbide (carbonitride) precipitate formation.