Mohammad Mahdi Esfahani - Master of Science in Material Engineering, Machine Sazi Arak
Ebrahim Roshanaei - Managing Director of Metallurgy Group Machine Sazi Arak
Alireza Nouri - Engineering Manager of Metallurgy Group Machine Sazi Arak
Mojtab Esmailzadeh - Assistant Professor, Persian Gulf University, Bushehr

In this study, the cold formation of pressure vessel sheet was investigated by using open-die pressingprocess. The rolled sheet of A516 Gr70 with thickness of 45 mm was selected. The radius of the die was6000 mm to pressing process. The process was carried out in three passes. In each pass, force of 600 tonswas applied. The process was performed in passes 1, and in order to reduce the effect of the springback and to check the effect of the repetition of formation process on mechanical properties andmicrostructure of the formed sheets. The results showed that the tensile strength, yield stress and hardnessare reduced at the first step of pressing process. In the following, the mechanical properties are increasedby repeating the pressing process in and passes. Microstructural analysis showed that the order ofrolling grains was disrupted and the orientation of the first grains would greatly change by performing thepressing process. By increasing the number of passes, the orientation of the grains become more uniformthat causes the enhancement of mechanical properties.

Open-die pressing, Pressure vessel, Mechanical properties