The titanium alloy rod continuous rolling production unit is an 8-stand three-roller Y-type rolling machine. The titanium alloy grade is TC4. The blank is a titanium rod with a diameter of 25mm. It is rolled through 8 passes to make a finished product with a diameter of 15mm. The original pass shape is flat. Triangle-circle-flat triangle-circle-flat triangle-circle-circle-round hole type. However, in actual production, the finished titanium alloy bars often have many problems such as ears that run through the entire length of the product, substantial torsion of the rolled piece, and poor roundness of the finished bar, which ultimately leads to substandard dimensional accuracy of the product. In view of the above problems, an idea is put forward: whether the flat triangular hole shape can be improved so that the improved flat triangular hole shape can reduce the torsion of the breast piece caused by the uneven circumferential flow of the breast piece metal, and at the same time reduce the distortion of the breast piece metal. The flow amplitude towards the roll gap in the round hole type.

  1. Based on the improved “flat triangle-circle” pass system and combined with ANSYS/LS-DYNA nonlinear finite element software, the deformation process of titanium alloy bars in the continuous rolling mill is vividly simulated.
  2. At the same time, the existence of the trapezoidal block also restricts the circumferential flow of the metal in the rolled piece, forcing the metal to extend axially, thereby increasing the pass elongation coefficient and increasing the pass reduction, which to a certain extent solves the problem of reduction due to the reduction. There are many problems caused by oversize. Existing equipment can also be fully utilized to increase the size of the blank and thereby enhance the processing capacity of the blank.
  3. From the final simulation results, it can be intuitively seen that the improved “flat triangle-circle” pass system can well improve the roundness of titanium alloy rods, thereby improving the dimensional accuracy of the product.
  4. The improved flat triangular pass type is equivalent to installing a circle of trapezoidal blocks at the bottom of the traditional flat roller. In this way, during rolling, the trapezoidal blocks are pressed into the rolled piece and the part where the rolled piece is pressed appears in the next pass. The sub-circular pass roll gap reduces the flow amplitude of the rolled metal to the roll gap, thereby reducing the occurrence of ears.
  5. The trapezoidal block pressed into the rolled piece also plays a role in positioning the rolled piece, which greatly reduces the problems caused by the uneven metal density of the rolled piece, the elastic recovery of the rolled piece, and the vibration of the rolling mill in the traditional flat triangular pass. The non-uniformity of the circumferential flow of metal in the rolled piece greatly reduces the probability of torsion of the rolled piece that is common in the traditional “flat triangle-circle” pass system.
    For titanium alloy rods, the traditional method is to use a horizontal rolling machine to reciprocate. In order to improve the mechanical properties and processing technology of titanium rods, it is necessary to use hot emulsion technology to produce small-sized titanium alloy rods. With the promotion of application scope and increase in demand, the quality requirements for titanium alloy products have further increased, which requires further optimization of the production and processing technology of titanium alloys.
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