Thermo-mechanical coupled simulation of hot stamping components for process design

Abstract

At present, hot stamping represents an innovative manufacturing process for forming of high strength steels, implying a sheet at austenite temperature being rapidly cooled down and formed into a die at the same time (quenching). This forming process is used for the manufacturing of automobile structural components with a strength of up to 1,500 MPa, thus enabling extensive cost savings and good crash performance. Better formability at elevated temperatures and lower springback are further advantages of parts formed by hot stamping. The Finite Element Analysis is an essential precondition for a good process design including all process parameters. This paper presents the finite element simulation of a hot stamping process by means of experimentally calculated material data and describes a number of procedures for the simulation of hot stamping, aiming at a notable decrease in computation time. For a faster calculation thermal and mechanical phenomena are decoupled in two simulation programs.

Tribological performances of new steel grades for hot stamping tools

“…To meet the need to form these new materials, hot stamping has been widely applied in the automotive industry [2] to produce car body-in-white parts with a high strength-to-weight ratio, which allows a reduction of the fuel consumption [3] and preserves the passengers' safety. Despite the advantages that the hot stamping leads in terms of (i) shorter process chain, especially in the case of direct hot stamping, (ii) increase of mechanical properties just after the deformation process and without the need of additional heat treatments, (iii) reduction of the total weight of the vehicles thanks to thinner components maintaining the frame stiffness, (iv) high shape precision [4], (v) absence of lubricants that are often hazardous for the environment and require expensive cleaning operations [5], friction and wear become particularly critical for the sheet sliding in the dies cavities and their service life [6] and the heating phase, with the subsequent inevitable contact with air during transport and forming, causes the oxidation and decarburization of the metal sheets [7]. For these reasons, the 22MnB5 steel sheets that…”

Thermo-mechanical finite element analysis incorporating the temperature dependent stress-strain response of low alloy steel for practical application to the hot stamped part

“…During the thermo-mechanical analysis, the following heat equation for thermally isotropic material was solved: (4) where C p , k, ρ, and t denote the specific heat capacity, thermal conductivity, mass density, and time, respectively. The term is the additional heat generation rate by the plastic deformation, phase transformation, and so on.…”

“…In order to optimize the process parameters, including tool settings, many FE simulations with thermo-mechanical coupled or thermo-mechanical-metallurgical coupled codes have been performed successfully [3][4][5][6]. To enhance the prediction capability of FE simulations for the hot stamping process, the proper thermo-mechanical-metallurgical properties of the steel should be provided.…”

Research on hot stamping for a typical part of B1500HS boron steel using experiment and numerical simulation methods

“…Tekkaya et al [10] presented the thermo-mechanical coupled simulation of hot stamping process by means of experimentally calculated material data and described a number of procedures for the simulation of hot stamping, aiming at a notable decrease in computation time. So et al [11] studied the warm blanking and cold blanking of 22MnB5 steel, and compared the results of experiment and finite element simulation.…”