TY - JOUR

T1 - Granular media-based tube press hardening

AU - Chen, H.

AU - Güner, A.

AU - Ben Khalifa, N.

AU - Tekkaya, A. E.

PY - 2016/2/1

Y1 - 2016/2/1

N2 - Press hardening process can benefit the formability of 22MnB5 in high temperature and high strength as a final product. It is widely used for weight reduction of car body without sacrifice of its crashworthiness. Nevertheless, not only strength but also stiffness is important for some vehicle components. Press hardening of tube using granular media is the possible technology to realize the press hardening process for tubular components, which have much higher stiffness as compared to sheet metal parts. To choose appropriate granular media, instrumented die compaction test and high pressure direct shear test were established to characterize the material property of granular material. A hot tensile test was used to determine the formability of 22MnB5 tube material. Interaction between granular media and tube material including friction coefficient and heat transfer coefficient was measured by shear test and heat transfer test. Based on these works, a thermal-mechanical coupled finite element model was used to analyses the process. In validation experiment, a T-shape specimen was formed and quenched. Process parameters such as loading force, interfacial friction, and tube geometry were also investigated via numerical and experimental research for a better understanding of the process. The interfacial friction between granular media and tube showed significant effects to the forming result. These effects were represented by process parameters such as friction coefficient, tube length, types of granular media. A multi-type granular media brought out higher pressure transfer effect and also reduced interfacial friction force, which showed better formability.

AB - Press hardening process can benefit the formability of 22MnB5 in high temperature and high strength as a final product. It is widely used for weight reduction of car body without sacrifice of its crashworthiness. Nevertheless, not only strength but also stiffness is important for some vehicle components. Press hardening of tube using granular media is the possible technology to realize the press hardening process for tubular components, which have much higher stiffness as compared to sheet metal parts. To choose appropriate granular media, instrumented die compaction test and high pressure direct shear test were established to characterize the material property of granular material. A hot tensile test was used to determine the formability of 22MnB5 tube material. Interaction between granular media and tube material including friction coefficient and heat transfer coefficient was measured by shear test and heat transfer test. Based on these works, a thermal-mechanical coupled finite element model was used to analyses the process. In validation experiment, a T-shape specimen was formed and quenched. Process parameters such as loading force, interfacial friction, and tube geometry were also investigated via numerical and experimental research for a better understanding of the process. The interfacial friction between granular media and tube showed significant effects to the forming result. These effects were represented by process parameters such as friction coefficient, tube length, types of granular media. A multi-type granular media brought out higher pressure transfer effect and also reduced interfacial friction force, which showed better formability.

KW - 22MnB5

KW - Granular media

KW - Press hardening

KW - Tube hydroforming

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84948572958&partnerID=8YFLogxK

U2 - 10.1016/j.jmatprotec.2015.03.028

DO - 10.1016/j.jmatprotec.2015.03.028

M3 - Journal articles

AN - SCOPUS:84948572958

VL - 228

SP - 145

EP - 159

JO - Journal of Materials Processing Technology

JF - Journal of Materials Processing Technology

SN - 0924-0136

ER -