Prediction model for surface cracking sensitivity of #br#
microalloyed steel continuous casting slab
DU Chenwei,LAN Peng,WANG Chunlei,ZHANG Jiaquan
(1. Jiujiang Pinggang Iron and Steel Co., Ltd., Fangda Group, Jiujiang 332500, Jiangxi, China;2. School of
Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China)
In order to solve the surface cracking defects of microalloyed steel casting slab from solidification and phase transformation aspects. The models of peritectic reaction, austenite grain growth, ferrite transformation and carbonitride precipitation during the initial solidification of microalloyed steels were established. The prediction model of slab surface cracking sensitivity related to the peritectic reaction degree, primary austenite grain growth, transformation of austenite to ferrite and carbonitride precipitation were further established combined with the real cooling conditions. For J55 steel, the surface transverse cracking sensitivity would reach the peak on the condition of the austenite grain large than 1 mm, the ferrite precipitation content of 10% and the increase of the continuous carbonitrides precipitation. The cracking sensitivity prediction model was helpful to realize the surface cracking control during the continuous casting and hot charging processes of the microalloyed steel based on the microadjustment of composition and structure.