Theoretical and Experimental Study of Non-Steady-State Pipe Reduction Process Using a Tesa 20-102 Mill

We describe the results of an experimental study of longitudinal and transverse variations in wall thickness at the ends of pipes after rolling in a stretch-reducing mill (SRM). We found that the largest “contribution” to the scatter in wall thickness comes from internal hexagon produced in the pipes by the reduction-mill drawing schedule and the roll pass design. A mathematical model was developed based on current high-speed SRM mode calculation procedures, and the plastic tension coefficients, rolling diameters, and roller speeds for each SRM stand in steady-state rolling mode were calculated. The pipe wall thicknesses calculated using the mathematical model were similar to those obtained experimentally. The accuracy of the pipe inside diameter was determined.