Technology of profiling a workpiece on forging rolls to reduce metal consumption and analysis of its stress-strain state

When implementing the technology of treatment by pressure of elongated forgings on crank hot forging presses, there are a number of restrictions on the use of blanking grooves. Upsetting operations, metal collection by upsetting in conical cavities of the tool, extrusion (forward, backward, combined) with a limitation on the length of the blank are allowed. However, when applying a deforming force transverse to the longitudinal axis of the blank, blanking-preliminary grooves, such as edging, blocking and finishing, are not designed, but their implementation is transferred to another type of equipment built into the process line. In our example, such auxiliary equipment is forging rolls. To reduce die steel consumption, the tool for them is made in the form of sectors. Several pairs of sectors-dies, according to the number of necessary rolling transitions, are placed on the working shafts of the forging rolls. An important circumstance is not only the possibility of placement, but also reliable fastening and fixation of the sectors on the shafts. The diagram of one of the clamping options is given in the article. According to known methods, the calibers are designed in accordance with the required dimensions of the workpiece. In addition, the results of modeling the rolling process of a profiled workpiece of the required shapes and sizes of characteristic sections are obtained. An analysis of the stress intensity and strain intensity, which are derivatives of tensor invariants, is carried out in a time-varying local deformation center of the workpiece metal, profiled using the technological operation of rolling with sector dies in grooves of constant cross section. The studies were carried out by computer modeling in the DEFORM-3D software package based on the finite element method (FEM). The results of the analysis are the dependencies of the change in stress and strain intensities at five monitored points of the cross section of the workpiece at three stages of rolling in oval and round calibers, as well as an assessment of the exhaustion of the metal plasticity resource according to the Cockcroft-Latham criterion.