Investigation of the effect of heat treatment on the structure of the cold-rolled ferrite stainless steels

Abstract

The work presents the estimation of a factor, namely, the solid solution super saturation by carbon and nitrogen on crystalline nature of high-chromium ferrite (HCF) in defining the inhibition mechanism of recrystallization processes in ferritic stainless steel. The essence of the study was to conduct an additional heat treatment of hot (h/r) tackle for the following modes: annealing 800 ° C - 4 hours, tempering with temperatures of 900, 1000, 1100 ° C after exposure to 1 min/mm. It is established that the determining factor that influences the amount of the carbide phase in c/r sheet is prior treatment of h/r tackle. A definite connection between the volume fraction of the secondary phase and the degree of cold deformation was observed. In the structure of cold-rolled sheet the same pattern with respect to the degree of implementation processes allocation of excess phases is maintained as in hot-rolled, after appropriate heat treatment. The smallest amount of the secondary phase structure was observed in the letter after hardening from 1100 °C - 1 min/mm. The reason is the thermodynamic state of HCF, to which at 1100 °C all the excess carbon and nitrogen must exist in solid solution. Thus, it is found that according to the present analysis of structural changes it should be noted that the best option of thermal prior treatment of h/r tackle is the annealing at 800 °C – 4 hours