Study On The Manufacturing Technology Of 2000m~3 Low Temperature Ethylene Spherical Tanks Using 09MnNiDR Steels

There were many difficulties in design, material choice, manufacturing and welding of low temperature ethylene spherical tank. For a long time, the tanks were designed by foreign companies and the steel plates (spherical plates), forgings and welding materials used for the tanks were imported from abroad. Then, the tanks were installed under the supervision of foreign experts. The tank's manufacturing cost was very high.In this paper, homemade manufacturing technology of 2000m3 low temperature ethylene spherical tanks was studied. Firstly, domestic materials such as steel plates, forgings and welding rods were chosen. The material mechanical properties and metallurgical structures after different heat treatments were investigated by the experiments. The results showed that the choosen materials will meet manufacturing requirements for the low temperature ethylene spherical tank.Secondly, the weldability of 09MnNiDR steel and the mechanical properties of weld metal in different heat treatment were tested experimentally. The optimal welding parameters were defined. The structure design and finite element analysis of spherical tanks were carried out. The results showed that the sizes of all parts of spherical tanks were reasonable and the tank's strength and stability were enough, which proved that the design of spherical tanks was safe and reliable.Finally, qualified ethylene spherical tanks were produced and put into operation. The goal of domestic manufacturing ethylene spherical tanks was achieved.