Experimental Study on the Forming Limit of GH605 Superalloy Sheet Using Digital Image Correlation

In this work, the forming limit of GH605 superalloy was determined by using digital image correlation analysis to monitor the strain evolution during this process. First, tensile experiments were conducted to determine the material constants of three different types of GH605 superalloys. Then, the Holmberg and Marciniak methods of forming limit tests were compared, and the complete forming limit diagram was obtained by combining the results from 6 specimens. Finally, the factors affecting the forming limit were analyzed, and the forming limit diagrams (FLD) of three different types of GH605 superalloys were obtained. The results showed that the forming limit curve of GH605 sheet and strip showed a typical ‘V’ shape, and the minimum forming limit appeared near the plane strain. The FLD of GH605 sheet was also obtained in this work, which is of great significance to numerical simulations of sheet metals and the formulation of process parameters.