Numerical Simulation using Finite Elements to Develop and Optimize Forging Processes

Abstract

Forging is one of the main processes used to manufacture metal components for a broad range of applications. This occurs mainly because forged products are highly reliable and present superior mechanical properties. However, lately the competitiveness of forged products has been threatened, since the difference between their superior performance and the performance resulting from other processes has lessened continuously. This has obliged the forging industry to invest in optimizing its processes, saving in raw materials and energy. In this context, the use of numerical simulation of the forging process has become an increasingly reliable tool in seeking this optimization. This study uses the commercial software QForm 3D, version 3.2.1.1, to analyse two forging processes, one by hot forging and one by cold. In the case of hot forging, work on a component with axial symmetry is looked at from which a gear is machined. Currently the part is forged in three stages based on an initial billet with a 7.0 kg mass. Forging is performed in a 40 NM mechanical press with an initial temperature of 1200°C. The hot forging process is optimized and this results in a saving of about 5% in material. In the cold forging case it is shown that the process, as designed, results in laps in the final part, and in possible tool failure due to excess load. In both cases, the material used is DIN 1.7131 (16MnCr5) steel.

A thermo-viscoplasticity model for metals over wide temperature ranges- application to case hardening steel

“…r mix = 0, is assumed. From yield curves obtained at different temperatures T i and different strain rates, found in [32], values of the initial yield stress y 0 (T i ), the saturation yield stress y ∞ (T i ) = ϕ κ (T i ) Y ∞ , the saturation coefficient k 0 (T i ), the characteristic time τ (T i ) as well as the viscosity exponent m(T i ) are identified for each of these temperatures individu-ally. For the parameter identification, only the part of the yield curves with the effective strain…”

“…Experimental data provided by [4,11,13,25,29,32] shows significant temperature dependency of the elastic moduli and B Philip Oppermann philip.oppermann@solid.lth.se Ralf Denzer ralf.denzer@solid.lth.se Andreas Menzel andreas.menzel@tu-dortmund.de; andreas.menzel@solid.lth. a coupled temperature and rate dependency of the plastic deformation behaviour.…”

“…interpolating between yield curves experimentally obtained at constant temperatures and deformation rates, as applied by, e.g. [32], or by using direct approximations of the yield curve, as discussed in, e.g. [15,18].…”

Finite‐strain thermo‐viscoplasticity for case‐hardening steels over a wide temperature range

“…The heat flux vector Q = Jq • F −t is modeled by the spatially isotropic Fourier's law q = −Λ(T )∇ x T . All model parameters are fit against experimental data from [3,4,6,7].…”

Numerical simulation of hot forging process in production of axisymmetric automobile parts

“…It may provide a means of substituting traditional preform design methods, effectively improving the level of forging-die design and controlling the quality of products through optimization of the process parameters [4,[7][8][9][10]. Optimization of the forging processes with numeric simulation has been talked about in numbers of research studies [5,6,[12][13][14]. Forging process, usually involve multiple pre-forming processes followed by a specified finishing process.…”