Evaluation of Formability of Thin Sheet Metal from Mechanical Properties
The evaluation of formability for sheet metals by means of different tests such as hole-expansion and forming limit tests is widely used in industry. The experimental efforts for these tests and the scatter of the results are much higher than those for the identification of the mechanical properties of various material charges for the same material grade in tensile test. Difficulties in accurate formability evaluation for new steel grades, such as AHSS, have necessitated a review of the existing prediction methods. Consequently, a new formability criterion was developed from the statistical relations of parameters for approximately fifty steel grades in various thickness ranges. The criterion considers the combination of mechanical properties from the tensile testing as the yield strength, tensile strength and total elongation and plastic deformation energy in a single value. The quality ranking of different charges and coils was made by using of the criterion as well as, for comparison, other well-known criteria which are currently used in the industry. The results obtained involving the new formability criterion seems to be accurate for a wide range of material grades and thicknesses, from the viewpoint of automotive design requirements.
Heinz Palkowski, Vladimir Yukhvid, Dmitriy Chernikov, Alexander Amosov, Fedor Grechnikov, Yuriy Klochkov, Ekaterina Nosova and Yaroslav Yerisov
S. Guk, "Evaluation of Formability of Thin Sheet Metal from Mechanical Properties", Key Engineering Materials, Vol. 684, pp. 80-85, 2016