Electrically-assisted Incremental Sheet Forming of Advanced High Strength Steels

In Electrically-Assisted Incremental Sheet Forming (EISF), the sheet specimen is locally heated by electrical current, which flows through the forming tool to the sheet specimen at their contact area, due to the well-known Joule heating effect. EISF Experiment was carried out on advanced high strength steel, DP1000. The maximum temperatures at the contact area between the forming tool and sheet specimen were monitored by an infrared camera and controlled through a feed-back control program during forming. Two DP1000 specimens were formed at the maximum temperatures of 600̊C and 800̊C. Both forming force and electrical current were recorded throughout the experiments. The effect of forming temperature on the forming force and required electrical current were analyzed. After the sheet specimens were cooled to room temperature, tensile specimens with reduced size were cut from the straight walls of the sheet specimens by electrical discharge machining, in order to investigate the effect of deformation at elevated temperatures on the post-deformation mechanical properties of the steel sheets.