Hot pressing process is very popular for thin plates in metal forming, such as in automotive construction. However, the process mechanism for very thick plates of high strength steel at hot temperature needs to be investigated. The process is characterized by thermo-mechanical behaviors, three-dimensional unsteady deformation and high nonlinearity. In this paper, the model of the process for manufacturing large and thick blades of Francis turbine is proposed. The process analysis is based on finite element method under ANSYS/LS-DYNA platform to get better understanding of the process. The whole process consists of the pressing forming of a blade from a flat blank, the springback after the forming and the cooling of the blade from hot temperature to room temperature. Investigation of the stress evolution is performed.
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