Determinations of the Non-Recrystallization Temperature for X52 Steel Produced by Compact Slab Process Combined with Direct Hot Rolling

Abstract

Deformation comprises not only dimensional accuracy but also the control of the final microstructure and mechanical properties. Deformation below the non-recrystallization temperature (T nr) is important to design the proper rolling schedule to avoid grain growth in the final stages of rolling. The determination ofT nr for Nb-bearing carbon steel with a compact slab process mill log is carried out depending upon the Misaka concept calculation. A comparison among different formulas for predicting theT nr was conducted using Misaka, Bratto, and Jonas equations. The Misaka equation depends on the chemical compositions and deformation parameters including dynamic and metadynamic recrystallization. The Bratto equation considers only the steel chemical composition. The Jonas equation depends only on the accumulated strain. The Bratto equation gives a large value ofT nr, while the Misaka equations show a moderate and accurate value in relation to the Jonas results, which depend on torsion tests. The effect of strain accumulation on dynamic recrystallization is investigated to predict the final grain size of ferrite.