Comparison of the Microstructural Effects between the BH Steel Obtained from Heat Treatment and the IF Steel of High Strength Concerning the Springback Effect

This work aimed to obtain microstructural changes due to the springback effect in order to compare two conventional high strength steels: the interstitial free steel (IF) and the bake hardening steel (BH). The mechanical characterization of the springback effect was performed by a mechanical forming testing called as the three-point air bending. The geometric changes resulting from the forming process were measured by calculating the aspect ratio. The results show that the BH steel suffers a greater springback effect rate than the IF steel due to the greater mechanical strength of the BH steel, and to the variation of this steel’s aspect ratio, depending on the combination of elongation and mechanical strength. It was concluded that the heat treatment performed on the BH steel increased the mechanical strength of the material without losing its formability.