Mathematical Model of Heat Transfer for Bloom Continuous Casting of Automobile Structure Steel

摘要

A mathematical model for heat transfer during solidification in continuous casting of automobile structure steel was established in researching on influence of the solidifying process on bloom quality of CCM in EAF steelmaking shop at Shijiazhuang Iron and Steel Co.Ltd.. Five steel grades were chosen to research, such as 40Cr, 42CrMo, gear steel and so on. According to the results of high temperature mechanical property tests of blooms, respective temperature curves for controlling solidification of different steels were acquired, and the simulating software was developed. Moreover, the model was verified through two ways, which were bloom pin-shooting and surface strand temperature measuring experiments. The model has provided references for research on the solidifying process and optimization of secondary cooling system for automobile steel. And it was already applied to real production. The calculated temperature distribution and solidification trend of blooms has offered reliable theory for optimizing solidifying process of blooms, increasing withdrawal speed and improving bloom quality. Meanwhile, a new secondary cooling system was designed to optimize secondary cooling water distribution, including choice and arrangements of nozzles, calculation of cooling water quantity, and so on.