The material of the dimethyl carbonate pressurized tower after over-temperature was analyzed.Through on-site inspection and testing,the circumferential expansion of the cylinder joint,the wall thickness of the cylinder joint,the macroscopic damage of the internal and external parts,and the metallographic structure,hardness and size change of the over-temperature parts were analyzed.Considering the requirements of the hardness value,the allowable stress of the material subjected to over-temperature damage was determined,and the strength of the over-temperature cylinder and open-hole reinforcement were checked.Through the analysis,it is found that the dimethyl carbonate pressurized tower basically meets the strength requirements,and it is recommended to carry out the opening reinforcement treatment at the manhole of the cylinder joint,so as to ensure that the dimethyl carbonate pressurized tower can continue to serve safely.