The Wellhead Forging Multi-directional Forging Process And Numerical Simulation Study

The wellhead forging is one of the most important products of oil equipment industry. The kind of forgings, which is heavy close-die forgings with a hole, concave side wall and double end flanges, not only requires high quality, but also has complex shape. The traditional process of this kind of forgings is open-die forging, which has a lower material utilization, a longer machining cycle, and, as a result, a higher cost. Multi-ram forging provides a new production way for this kind of forgings while the forging amount is higher. So far, study on this type of multi-ram closed die forging process and its numerical simulation are relatively little.In this article, the author briefly introduced the features of the wellhead forging, and particularly introduced the studies of the multi-ram closed-die forging and numerical simulation.By the use of the CAD system of UG, the three-dimensional model of a wellhead forging and its die have been set up parametrically. Based on the rigid-plastic finite element method, The forming process of the wellhead forging has been simulated by using the finite element numerical simulation software DEFORM-3D. The rule of metal flow, the distribution of the strain, stress, temperature field, as well as the stroke-load curve of the forming process have been obtained and analyzed through simulation results. On this basis, we studied different friction coefficients, different velocity, different temperature, different radius, and different thickness of wad, which influence on the forming process. The better loading parameters were found as follows, the friction coefficient : 0.3, velocity: 8mm/s, temperature: 1150℃, radius: the first group, thickness of wad: 30㎜,These parameters provided better result for the wellhead forging. Through simulation, process parameters of the heavy close-die forging such as the forming load, the lock-die force and the maximum stress etc. were also obtained, which provided useful date for the design of the multiple-ram closed-die forging and the design of dies.