Quantitative formability estimation of ring rolling process by using deformation processing map

Studies on quantitative formability estimation by using deformation processing map have been performed to estimate deformation characteristics of SAF2205 duplex stainless steel during ring rolling process. To develop deformation processing map, dynamic materials model has been used on the basis of stress-strain relationships from Gleeble compression test. As a quantitative formability index, summation of ηij (efficiency of power dissipation for i-th unit deformation group in j-th slicing plane) multiplied by area fraction of unit deformation group (Aij) has been suggested. ηij-value for unit deformation group was determined from deformation processing map of which temperature and strain rate can be obtained by finite element method. For the feasibility analysis, the optimum blank dimension at various operating temperatures has been determined on the basis of formability index. The analysis result strongly confirms that the proposed formability index can provide a reliable guide in process design of ring rolling process.