In order to eliminate the mixed crystals of the thick-walled heavy cylinder after rolling and improve the quench shortage of tank copious cooling, it is significant to analyze the cooling capacity of spray cooling and tank copious cooling. Models of heat transfer coefficient about spray cooling and copious cooling were established. The quenching process simulation was made based on the DEFORM software. The cooling rate models of center part about spray cooling and copious cooling were build. According to the CCT curves of heavy cylinder material and simulation results, which show that: (1) Using spray cooling can increase the cooling rate of center part to some extent and improve the mechanical properties. (2) The maximum capacity of spray cooling is 280mm, that is the microstructure of center part fully transfers to bainite, which is 50mm larger than copious cooling.

In the present work, detailed studies were made on the transformation characteristics, microstructure and mechanical properties of heavy shell ring (HSR) in the spray cooling process. The spray cooling device of HSR was designed. The 2.25Cr1Mo0.25V steel used in production of HSR for hydrogenation reactor was selected as the testing material. The simulation of spray cooling of HSR was carried out on ABAQUS. The constitutive model and continuous cooling transformation (CCT) diagram of 2.25Cr1Mo0.25V were determined. CCT diagram, metallograph and SEM results show that the bainite forms throughout the cooling rate range from 0.5 to 10 ℃/s, and martensite begins to be produced by increasing the cooling rate higher than 60℃/s; when the cooling rate is 10 ℃/s, with the increase of the deformation degrees, the ferrite grain size becomes small, the yield strength and tensile strength increase, the elongation decrease, So it is good for refining the grain to increase the deformation. The yield strength, tensile strength and elongation were obtained under different cooling technology.