The three-high screw rolling of AISI 321 billet from 60 mm to 52 mm diameter was performed using an MISIS-100T mill. When screw rolling was carried out, a set of sections were made in the billet’s cross-section at the stationary stage of screw rolling. SolidWorks was applied to make the 3D model of the rolled billet’s grain using microstructure images. The same technique was applied for the creation of the 3D model of a nondeformed billet’s grain. A comparison of the 3D models’ shape and dimensions before and after screw rolling was made. It was established that, compared to the nondeformed grain model, the screw rolled billet’s grain model was twisted and elongated along some angle in the rolling direction. This angle’s value is commensurable to the roll’s feed angle during the experimental rolling. Anisotropy indexes of before and after rolling grain models were estimated and compared to the anisotropy indexes obtained via the sections’ analysis in earlier research. Difference did not exceed 5%.

The paper discusses the specific aspects of hot rolled seamless pipes manufacture using pipe rolling plants including screw-rolling mills. The method of accuracy enhancement of pipe dimensions, as well as external and internal surface quality improvement, is proposed. The article specifies the results of computer and physical modeling of the pipes mandreling process. The application of the mandreling process within the cage using different diameter mandrels is shown. We managed to decrease the typical mark caused by the metal deformation, due to the screw-rolling mill and to manufacture pipes with more accurate dimensions, as a result of the mandreling process modeling. The results of the physical experiment on mandreling the shell pierced at the screw-rolling mill showed a positive effect from the process of hollow billet cold treatment using the mandrel.

The finite element method (FEM) computer simulation of the three-high radial shear rolling of Ti-6Al-4V alloy round billets was conducted using QForm software. The simulation was performed for the MISIS-100T rolling mill’s three passes according to the following rolling route: 76 mm (the initial billet diameter) →65 mm→55 mm→48 mm (the final billet diameter). The change in the total velocity values for the points on the radius of the 48 mm diameter billet was estimated while passing the rolls’ draft. The relative increase in the accumulated strain was estimated for the same points. Then, experimental shear rolling was performed. Grain sizes of the α- and β-phases were estimated in the cross section of the final billet at the stationary stage of rolling. The grain size distribution histograms for different phases were plotted. An area was found in the billet’s cross section in which the trend of change in the total velocity of the points changed. This area represented a neutral layer between the slowing peripheral segments of the billet and the accelerating central segments of the billet. Inside this neutral layer, the limits of the cylindrical surface radius value were estimated. Experimental radial shear rolling was performed to compare the experimental rolling results (the billet microstructure investigation) with the computer simulation results. The computer simulation obtained two estimations of the radius limits: 8–16 mm (based on the analysis of the total velocity change) and 12–16 mm (based on the accumulated strain’s relative increment change). The experimental rolling obtained two more estimations of the radius limits: 8.4–19.5 mm and 11.3–19.7 mm—based on the results of the microstructure investigation. It was confirmed that varying the kinematic and deformation parameters of radial shear rolling allows regulation of the thickness of the peripheral fine-grain layer and the diameter of the central coarse-grain layer of the rolled billets.