Research On Influence Of Billet Shape And Dimension On Blade Die Forging And Energy-saving Material-saving

The turbine blade called the heart of steam turbine is the key parts to change steam energy into mechanical work Die forging always is main process method of the blade production. There are much factors influencing quality of blade forging, also includes billet shape and dimension. To quantitatively design cogging mode, billet structure and optimize ingot volume has the extremely important practical significance for effectively shortening production debugging time, saving material and energy, reducing prime cost and volume-forging blades qualified.With developments of the computer technology and computational method, by means of numeric simulating experiment one not only can understand the process of billet deformation and filling die, forecast and control product quality, confirm forging defect type, position, cause and influencing factor, so as to improve and optimize forging structure, billet shape, die forging condition and craft parameter, reduce test-forging and enhance material utilization, but also can analysis the position and reason of die failure under the action of force-heat alternate load, so as to improve and optimized die structure. Thereby, to avoid the waste of labor, physical and financial resources from again and again test-forging and die-debugging by the conventional method and increase the technology and economic benefit of blade production.In this thesis, for solving the material utilization and energy-saving in the blade die forging process the influences of billet shape and dimension on blade die-forging quality and die functional mode are studied by the finite element software DEFORM-3D. A feasible cogging structure is determined through comparing and analyzing influence of different billet structure on deformation temperature and equivalent stress/strain. The billet dimension and volume are optimized through forward simulating technology and golden section method. The potential position of die failure is forecasted and the approach keeping die from failure is put through analyzing the die functional mode.The numerical simulation results indicate, under the condition of volume-invariableness, to adopt the billet of round-flat as root section and round as body section not only is advantageous to the metal flow uniformity in the process of blade die forging, but also is convenient in the actual operation. Under the precondition of insuring die forging quality and billet shape given, the blade material can be saved through controlling the flash mass or reducing billet volume. High-temperature and high-stress acting reciprocally on the local region of die cavity is one of the important reasons for causing the die premature failure. Thus these may be known that the shape and dimension of billet will affect metal filling die-cavity, energy-saving and material-saving in die forging process. Determine reasonable billet shape and dimension for forging blade, not only can effective increase the material utilization, but also can reduce properly the number of blows, decrease the probability of die failure and save forging energy.