Why do seamless steel pipes wrinkle during production?

Wrinkling in the production process of seamless steel pipes will lead to the scrapping of parts, which will not only increase the production cost, but also waste raw materials, causing losses to the factory and customers.

Causes of wrinkling:

1) The blanking force of the seamless pipe is not good, and the gap on the surface of the pressure material is not suitable for the problem of "loose inside and tight outside";

2) Too much lubricant, too frequent brushing, or inappropriate coating orientation for seamless pipes;

3) The experimental seamless steel pipe blank is too soft, the material strength is low, and the blank size is too small;

4) The positioning of the blank is unstable, resulting in local inability to press the material, and the shape of the pressing surface is improper, resulting in uneven feeding;

5) The stamping direction is incorrect.

Solution:

1) Check the wrinkling state. When the wrinkling occurs evenly around the part, it should be judged that the pressure is insufficient, and the gradually increased pressure can be eliminated. When drawing cones and hemispheres, deepened ribs should be added to increase the internal tensile stress of the steel plate to eliminate wrinkles, and the principle of "tight inside and loose outside" should be adopted to eliminate the problem of "loose inside and tight outside".

2) As for the lubricating oil, the oil brushing work should be carried out in accordance with the operating procedures and system requirements to ensure the correct brushing orientation and oil amount to avoid wrinkling.

3) Replace the material of the seamless steel pipe blank to ensure the quality of the part and avoid wrinkling without affecting the requirements of the whole vehicle.

4) Improve the positioning and add a pre-bending process if necessary to ensure that the material will not deviate when stamping the part. Modify the shape of the binder surface to ensure the quality of the parts and avoid the shape of the binder surface from moving, resulting in uneven feeding.

5) For the improper stamping direction, the simulation software should be used to analyze the part process in the early stage of design to ensure the stamping direction of the part. When the quality of the part is high, it is necessary to redevelop the mold and adjust the seamless steel pipe stamping direction.

Unlike welded steel tubes, seamless steel pipes are long strips of steel with a hollow section and no seams around them. The specifications of seamless pipes are expressed in millimeters of outer diameter * wall thickness. Its features include:

First, the thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, the higher its processing cost will be. Second, the process of the product determines its limited performance. Generally, seamless steel pipes have low precision, uneven wall thickness, low brightness inside and outside the tube, high cost of cutting to length, and pits and black spots on the inside and outside are not easy to remove. Third, its detection and shaping must be processed offline. Therefore, it embodies its superiority in terms of high pressure, high strength, and mechanical structural materials.

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