Numerical Analysis of a Six Stage Forging Process for Producing Hollow Flanged Parts from Tubular Blanks

Abstract

This paper presents the results of a numerical analysis of a cold forging process for a hollow flanged part. The analysis was performed using Deform 2D/3D. 42CrMo4 steel tubes were used as the billet material, and their material model in the annealed state was described by a constitutive equation. The forming process was performed in six stages with the use of methods such as extrusion with a movable sleeve, open-die extrusion, and upsetting. The objective of the study was to determine whether the proposed forging technique could be used to produce hollow parts with flanges. The determination was made based on the analysis of product geometry quality and process parameters, including the Cockcroft-Latham ductile fracture criterion and forming forces.

Effect of Annealing Time and Temperature Parameters on the Microstructure, Hardness and Strain-Hardening Coefficients of 42CrMo4 Steel

“…As a results was shown, among others, forging shape, force parameters as well as stress and strain distributions. The metal forming simulation parameters are described in detail in [35,36] in relation to the cold metal forming of 42CrMo4 steel parts. Finally, the effects of computer modelling were validated by experimental upsetting of samples.…”

“…It is known that especially for steels, the coarser grain size decreases mechanical properties such as hardness and yield strength, and can facilitate steel deformation [6,18,41,42]. Summing up, the annealing scheme 1 is recommended for manufacturing cold-metal formed parts in the future [35,36].…”

“…Additionally, many researchers have stressed the importance of calculating strain hardening coefficients such as a strength coefficient, c, and a strain hardening exponent, n. They are particularly essential when selecting heat treatment technological parameters or elaborating metal forming technology for steel [22,23], aluminium alloys [24,25], magnesium alloys [26,27], pure copper [28], powder metallurgy materials [29,30] or plasticine [31,32] or even MMC materials [33,34]. Therefore, this paper investigates the effect of annealing on the strain hardening parameters, the c and n coefficients are determined and can be used in numerical simulations and experimental tests of 42CrMo4 steel components dedicated for metal forming [35,36].…”

Theoretical and Experimental Analysis of a New Process for Forming Flanges on Hollow Parts

“…In effect, it is possible to form flanges with a relatively big diameter, and thickness decreasing insignificantly with increasing flange diameter. Other flanging methods presented in [7][8][9] involve extrusion with the use of a movable sleeve. In this process, the sleeve is moved in an opposite direction to that of the punch, and the tools create a closed die cavity of an increasing volume.…”

A New Method of Flanges Extrusion in Hollow Products – Analysis of the Limiting Phenomena

“…In the works [13,14] using the movable counter punch increases the height of the closed impression, which allows one to produce a flange with relatively significant heights in relation to the wall thickness of the tube billet. In the technologies based on extrusion with a movable sleeve, moving spontaneously as a result of pressure force of the deformed material [15] or powered independently from the punch [16,17] the volume of the closed impression increases along with the stage of the process. This phenomenon eliminates local buckling and folding, due to which it is possible to obtain flanges of the heights difficult to obtain with conventional methods.…”