Investigation of the influence of ovality of finishing caliber of three-roll continuous mandrel FQM mill on rolled product forming

Analysis of the production technology of seamless pipes for pipe-rolling units with continuous type PQF, FQM mills was carried out. Investigation of the influence of ovality value of finishing caliber of three-roll continuous mandrel FQM mill on rolled product forming was performed. Based on the results of simulation of rol¬ling technology in “Deform-3D” software the distribution of the wall thickness of the rolled product along the perimeter of the cross-section of the deformation zone at the outlet of the fifth stand of FQM mill was obtained as a function of the value of caliber ovality. The changing of the wall thickness of the rolled product in the taper of groove (on the parting line of the rolls) and in the outlet zone was obtained. Influence of the ovality of finishing caliber on the value of broadening of the rolled product, the contact zone between mandrel and rolled product, and the absolute non-uniformity of the wall thickness along the perimeter of the deformation zone was determined. The lowest absolute non-uniformity of the wall thickness, thickening at the taper of the groove, and tolerance zone of the wall thickness was obtained when the caliber with the ovality of 1.03 was used. The rolled product broadening coefficient, the area of the product in the deformation zone, the angle of contact between mandrel and rolled product also have maximum values for the caliber with ovality of 1.03. No overfill of the caliber was observed at all stages of simulation.