Abstract: The main material of AP1000 steel containment is SA738 Gr.B ultra-heavy plates. With the traditional rolling method， the deformation depth is limited and the core toughness is insufficient， which is mainly due to the blank size and the rolling mill capacity limitation. The high-permeability rolling process integrated by rolling-cooling is expected to improve the performance of the thick plates. The influence of high-permeability rolling process on the rolling deformation of a thick steel SA738 Gr.B was analyzed by numerical modeling and experiments. The results show that in order to obtain the same thick-direction rolling penetration effect， the single-pass reduction rate required for the high-permeability rolling process with a thickness-to-temperature difference of 300℃ can be reduced by 3%~4% compared with conventional rolling. Comparing with the experimental results， it can be seen that the high-permeability rolling process can improve the degree of metal deformation of the core and make the metal flow of each layer more uniform simultaneously.

Key words: ultra-heavy plate, SA738 Gr.B, high penetration rolling, low compression ratio, deformation permeability