The tested steel 12Cr2Mo1R (/% : 0. 08C

0. 07Si

0.45Mn

2.16Cr

0.95Mo

0.18Ni

0. 14Cu

0. 015Al

0.015Sn) is melted by EAF then electro-slag remelted to 300 mm x 2 000 mm slab and rolled to 150 mm heavy plate (Opening rolling 1145℃

final rolling 850℃). The static continuous cooling transformation ( CCT) curves and the cooling temperature curves of surface

1/4 thickness and 1/2 thickness ( center) of ultra-heavy plate of steel 12Ci2Mo1R are obtained by thermal simulation test and finite element simulation of temperature field. With normalized at 916 °C for 226 min and tempered at 698 °C for 240 min the structure of hot rolled plate at 1/4 thickness is bainite + minor ferrite

and that at 1/2 thickness is bainite + ferrite

its mechanical properties are yield strength 464 MPa

tensile strength 585 MPa and elongation 22% to meet the requirement of user.