Research On Multi-directional Die Forging Process Of Casing Head

The wellhead equipments play a significant role in the petroleum exploitation industry, while casing heads are the key device connecting the casing pipe and the wellhead. In order to solve the situation on the oil shortage and the low exploitation rate, a higher level of requirements for the quality and the demand of the casing head have been put forward with the rapid development of industrial technology. During the productive process of casing heads, it's especially urgent to not only improve the material utilization ratio, the production efficiency and the mechanical properties of forgings, but also reduce the cost of production.In this paper, the domestic and international research situation of valve bodies forgings and the development of multi-ram closed-die forging are introduced firstly. The true stress-strain curve of the forged steel 42 Cr Mo has been obtained by the Gleeble thermal/mechanics simulator. Then Key files is created and put into Deform-3D as the material of workpieces for finite element simulation. The constitutive equation for high temperature deformation of the material is obtained. According to the shape structure of casing head forgings with single, double flanges and the characteristics of the multi-ram die forging, the machining process route is made. Various schemes for multi-ram die forging are drawn up. The 3D model is established by UG and the finite element simulation is carried out with Deform-3D.The reasonable forming pass, die structure, billet size and loading sequence of casing head forgings with single, double flanges are optimized and determined through the analysis of the factors, such as forging forming effect, defects formation and the forming force of the casing head in each schemes. Finally, the optimal forming scheme for each forging is gained. The smaller forming force, the longer die life and the more reasonable distribution of metal streamline are ensured. At the same time, it can effectively avoid the folding, unfulfilled and burr defects. To further verify the reliability and safety of the optimal scheme, the change regulation on strain field, temperature field, velocity field, time-load of all dies and die stress at the typical moment of the forming process are researched.The above contents have been analysed through the simulations. Then, the new production processes for casing head forging with single, double flanges have been ensured. The advantages, disadvantages and the law of the forming pass, die structure, billet size and loading sequence have been summarized. It can provide the theoretical basis and reference for the actual production of the factory which depends on the multi-ram die forging process to produce the casing head with similar characteristics.