The manufacturing method of large diameter flange is usually made of steel plate cutting, cold bending or rolling, and then it is machined by large vertical lathe. The standard size of large diameter and the size of the standard are in accordance with the standard specifications.
In the process of making large diameter flange, the production equipment of steel plate cutting method is the most simple, the investment is small, and the material utilization ratio is low. It is also very simple for standard size setting.
Cold bending method is the first blank forging billet, and then cold bending into the arc section, annealing stress after heat treatment, the whole circle in the vertical to the shape and size of the design process. In fact, the whole process is a cooling and bending process, but in this process need to pay attention to the temperature and the degree of bending.
The material utilization ratio of the rolling process is high, and the subsequent machining allowance is smaller than that of the steel plate cutting, but it is restricted by the equipment. At present, the maximum diameter of flange manufactured by this method is only 4m.