Grain Size Modeling during Hot Rolling of a Nb Microalloyed Steel Beam

摘要

Hot rolling of structural beams is carried out essentially in two stages. Roughing is performed in a reversing mill at temperatures above 1100 ℃, relatively low strain rates and long interpass times. Finishing is carried out in a reversing three stand mill at temperatures between 1050 and as low as ~ 700 ℃, considering parts of the web in the last passes. In this stage strain rates are moderate and interpass times are in the range of 5 to 20s. Roughing and finishing stages of structural beams are to some extent similar to those of plate rolling. Technology for themomechanical processing, TMP, of Nb microalloyed steel plates is well known. Application of this technology to beam rolling is, on the other hand, less widespread. This paper addresses an application of TMP plate technology to structural beam rolling. The focus is to model austenite grain size evolution.