RESEARCH AND PROCESS-OPTIMIZATION ON MIXED CRYSTAL CAUSED UNEVEN-PERFORMANCE OF HIGH-STRENGTH STRUCTURAL CAR STEEL QSTE500TM

摘要

Handan Iron and Steel production of high-strength structural car steel QStE500TM thin gauge products using Nb + Ti composite strengthening, with a small amount of Cr element to improve its hardenability, the process parameter control is inappropriate with Nb + Ti complex steel, it is easy to produce in the mixed crystal phenomenon, resulting in decreasing the toughness and uneven performance. In this paper, deeble 3500 thermal simulation testing machine for high-strength structural steel car QSfE500TM product deformation austenite recrystallization behavior research, determined completely recrystalhzed, partial recrystallization and non-recrystallization region, provide theoretical basis and necessary data for reasonable controlled rolling process for production.