The coke drum is the core equipment of the delayed coking unit in the refining industry. It converts low-value inferior oil into high-value gasoline and middle distillate, which has enormous economic benefits. Due to the process characteristics of delayed coking, the coke drum is continuously subjected to heating and cooling cycles, usually within 28 to 48 hours. It needs to be cyclically changed from room temperature to about 500℃, and the medium to which the container is subjected is from a gaseous state to a liquid state to a solid state, and the working environment is complicated and bad. So whether it is design, material selection or manufacturing, there are high requirements. With the further development of manufacturing technology and the shortening of cycle time, the manufacturing requirements of coke drums are getting higher and higher. It has developed from ordinary materials 20g, 20R, 15CrMoR to SA387 Gr11 Cl1, SA387 Gr11 Cl2 and other high temperature performance and impact toughness. Bainitic heat resistant steel. Due to the above-mentioned harsh working environment of the coke drum, and the shortening of the cycle period, the toughness requirement of the coke drum material is getting higher and higher, and even the low temperature impact toughness requirement is put forward.
