STUDY OF THE RECRYSTALLIZATION BEHAVIOR IN Nb-BEARING STEELS BY MULTI-PASS, DOUBLE HIT AND STRESS RELAXATION TESTS

摘要

High deformation under Tnr is a common industrial practice to achieve a good combination of toughness and strength in HSLA steels. To combine the optimum combination of high productivity and product quality, an accurate knowledge of Tnr and the recrystallization kinetics in general is required. In this study, different mechanical tests (torsion, compression) and analysis methods (multiple hits, relaxation) are used to determine the recrystallization kinetics. The results prove that the methods available in the literature to analyze the different tests lead to non-consistent results. Recommendation for the analysis of the different tests is then formulated. Multi-pass torsion tests have been used and compared with empirical relationships from the literature. A significant discrepancy has been found between our experimental evidences and the literature results.