Stability of the Rolling Process and Selection of the Metal Tension Mode in the Wire Rod

The analysis of continuous long rolling processes taking into account the tension of the rolled specimen in the inter-stand intervals is relevant and has significant practical significance. Determination of standard machining modes with the exception of partial or complete slippage is based on estimates the longitudinal stability of the process using the average resulting internal forces of the plastically deformable metal. The issue of the longitudinal stability is the particular importance in continuous rolling with strip tension, when the rear tension of the specimen is greater than the front tension. The article analyzes the influence of the changes in specimen tension mode on the longitudinal stability of rolling at wire rod with a diameter of 5.5 mm in a wire block at mill 400/200. Taking into account the equilibrium of contact and internal forces in a plastic deformed metal, it is shown that a stable flow of metal in the deformation zone is possible only with average resultant longitudinal internal forces directed opposite to the movement of the metal in the rolls. With the changing in the tension mode (with an increase in their values), the longitudinal stability of the metal in the rolls deteriorates, which under certain conditions leads to slippage. Therefore, when rolling wire rod in a wire block, the specific stress should not exceed (0.04...0.06) of the average resistance to plastic deformation in this pass.