Parameter identification of 42CrMo4 steel hot forging plastic flow behaviour using industrial upsetting presses and finite element simulations

Abstract

An experimental-numerical methodology was proposed for the parameter identification of constitutive laws, when applied to hot forging. Industrial presses were directly used to generate the reference experiments for identification. The strain and temperature heterogeneity that appears during on-press compression experiments was taken into account by an FE-based inverse method. Specific experiments were designed for the identification of the heat transfer and friction coefficients. A testing tool was designed and instrumented with displacement sensors and a force cell. This was then used on a hydraulic press and a screw press in order to cover a large range of strain rates. The identified parameter set was validated with respect to specialized plastometers, and a semiindustrial validation forging process. A reasonable accuracy was observed, particularly in realistic forging conditions.

Effect of Sample Geometry on Strain Uniformity and Double Hit Compression Tests for Softening Kinetics Determination

“…It is important to note that these simulations have not taken the practical variability seen in these tests into consideration, with the UCT being known to show thermal gradients along its length [18,29] as well as variability in friction coefficients due to anvil wear and choice of lubricant. [30][31][32] PSCT can be much less sensitive to these variables depending on the experimental setup (such as in a HDS-V40 Gleeble where the hot portion of the sample is not in contact with the anvils prior to deformation).…”

Analysis and Improvement of an Industrial Process of Hot Die Forging of an Elongated Forging Tipped with a Joggle with the Use of Numerical Simulation Results

“…This is especially justified in the case when the forging has a complex shape such as that of a turbine blade, a toothed gear, a yoke, etc. [17][18][19][20][21][22][23][24][25][26]. In turn, the authors of [17] developed an experimental-numerical methodology of identifying coefficients for constitutive equations in the case of die forging on presses.…”

“…[17][18][19][20][21][22][23][24][25][26]. In turn, the authors of [17] developed an experimental-numerical methodology of identifying coefficients for constitutive equations in the case of die forging on presses. The article [18] uses FE modelling for the simulation of a process of quenching with water of a forged block made of high durability steel, in order to determine the deformation and residual stresses.…”

Parametric identification on a dynamic behavior model for a forging machine

“…To identify the parameters of such an experimentally based model, numerical optimization methods are required. And to guaranty the unicity, the accuracy and the reliability of the identified parameters, the target function has to be well defined [10] and a sensitivity study can be performed. In this study, the method developed in a previous work to determine a dynamic model based on experiments [9] will be applied on a screw press.…”