Forming limit diagrams of tailor rolled blank in hot stamping and its verification

Abstract Tailor rolled blank (TRB) with graded thickness has shown great potential in the automobile field. Using traditional forming limit diagrams (FLDs) to evaluate TRB formability is challenging due to thickness variations. In this paper, a 3D forming limit surface (FLS) considering the influence of thickness was obtained. A numerical model was developed to predict final strains. Moreover, a forming margin was denoted and calculated to generate the forming limit margin field graph for quantitative evaluation of the TRB formability. Results showed that as the punch travel increased, the forming margin value decreased. As the travel changed from 35.2 mm to 37.4 mm, the corresponding forming margin value changed from 0.002 to -0.024. The formability declined, and the specimen eventually cracked on the thinner side. Besides, the deformation and strain paths predicted by simulation agreed well with those measured from formed part, which indicated that the final strains used in formability evaluation were reliable. The method was suitable for quantitative evaluation of the formability and predicting the cracking position in TRB forming.

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Prediction of Forming Limit Diagrams for 22MnB5 in Hot Stamping Process

Journal of Materials Engineering and Performance ◽

10.1007/s11665-013-0491-5 ◽

2013 ◽

Vol 22 (8) ◽

pp. 2131-2140 ◽

Cited By ~ 26

Author(s):

Hongzhou Li ◽

Xin Wu ◽

Guangyao Li

Keyword(s):

Hot Stamping ◽

Forming Limit ◽

Forming Limit Diagrams ◽

Stamping Process

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Development of a New Biaxial Testing System for Generating Forming Limit Diagrams for Sheet Metals Under Hot Stamping Conditions

Experimental Mechanics ◽

10.1007/s11340-016-0183-9 ◽

2016 ◽

Vol 56 (9) ◽

pp. 1489-1500 ◽

Cited By ~ 26

Author(s):

Z. Shao ◽

N. Li ◽

J. Lin ◽

T. A. Dean

Keyword(s):

Hot Stamping ◽

Forming Limit ◽

Testing System ◽

Sheet Metals ◽

Biaxial Testing ◽

Forming Limit Diagrams

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Formability of AA6082-T6 at Warm and Hot Stamping Conditions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.716.107 ◽

2016 ◽

Vol 716 ◽

pp. 107-113 ◽

Cited By ~ 5

Author(s):

Xi Luan ◽

Omer El Fakir ◽

Hao Xiang Gao ◽

Jun Liu ◽

Li Liang Wang

Keyword(s):

Sheet Metal ◽

Hot Stamping ◽

Forming Limit ◽

Test Rig ◽

Forming Limit Diagrams ◽

Promising Technology ◽

Major Strain ◽

Forming Temperature

Forming limit diagrams (FLDs) of AA6082 at warm/hot stamping conditions were determined by using a specially designed test rig. The tests were carried out at various temperatures from 300 to 450°C and forming speeds ranging from 75 to 400 mm/s. The strain was visualized and measured using ARGUS software provided by GOM. The results clearly show that the formability of AA6082-T6 sheet metal, in terms of the limit major strain, increased by 38.9 % when the forming temperature was increased from 300°C to 450°C at a speed of 250 mm/s, and increased by 42.4 % when the forming speed was decreased from 400 to 75 mm/s at a temperature of 400°C. It was verified that hot stamping is a promising technology for manufacturing complex-shaped components.

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