Forming Process Research Of Gas Turbine Disk

Gas turbine disk adopt the new soft sheath-forging technology which is complex inproduction. The new soft-sheath-forging technology is in trial. Until now, there are noreliable and comprehensive research results about the temperature, strain, stress,damage and structure in the process for reference. With the localization speed ofsuperalloy turbine disk becoming faster and faster, the new producing process is neededmore compellingly. So, we need to go into the theory and experimental research aboutthe process of the waspaloy turbine disk.The process of gas turbine disk’ forging and the mould preheating were studiedwith the method of theoretical analysis, experiment, and finite element numericalsimulation based on the theory of rigid visco-plastic, plasticity, hydromechanics, heattransmission and so on. The main methods of the study are as follows:①The hot deformation behaviors of waspaloy nickel-based alloy were investigatedby hot compression tests and hot tensile test through which the true stress-true straincurves and the temperature-elongation were obtained. Some basic data of waspaloy wasobtained through these tests.②The forging process of YJ250turbine disk was simulated by the softwareDeform-3D and the temperature, stress, strain, damage and microstructure of billet wereanalysed.③T he die preheating process was simulated by the softwareANSYS/FLOTRANto investigate the effect of the preheating.④The problems appearing in the forging process were analysed by numericalsimulation and field trial. The solution methods were pointed out at last.The main conclusions obtained from this work are as follows:①T he forging process of soft sheath can be simulated by the software Deform-3D.The cracks appearing on the surface of forgings can be analysed and predicted by theductile fracture criterion of Normalized Cockcroft&Lat ham.②The die preheating process can be perfectly reappeared by the softwareANSYS/FLOTRAN, and the simulating results were accuracy and reliable.③T he main reasonleading to the end forging craking is that the initial forgingtemperature is too low.④The reason leading to the underfilling defect was that the volume laying-off was too small and some volume at the two ends of billet was brushed off when machiningthe testing surfaces.⑤The forging cracking and underfilling defects can be avoided by adopting theimproved process(the blanking size is φ120×210mm) and made the microstructuredistribute more reasonably.