The Reasons and Measures of Uneven Thickness of Thick - wall Steel

Thick steel pipe uneven is mainly reflected in the spiral wall uneven, linear wall thickness uneven and head and tail wall thickness thick, thin and so on
The cause of the uneven thickness of the spiral thick-walled steel pipe is that the centerline of the punching machine is not correct, the inclination of the two rolls is equal or the weight of the top is too small. The adjustment of the wall thickness is uneven, Distribution. The main measure is to adjust the punching machine center line, so that the two rollers of the same angle, according to the rolling table to adjust the parameters of rolling mill.
The reason for the uneven thickness of the linear wall is that the height of the mandrel pre-saddle is not suitable, and when the mandrel is pre-penetrated, it comes into contact with the capillary of a certain face, causing the capillary to drop too fast on the contact surface, resulting in uneven wall thickness Concave defect. The roll gap is too small or too large. Rolling mill centerline deviation. Single and double rack reduction uneven, will cause the direction of the single-frame steel ultra-thin (thick), double-frame direction thick (thin) linear symmetry deviation. The main measure is to adjust the height of the mandrel pre-wear saddle, to ensure that the mandrel and capillary tube. Replace the roll and rolling specifications should be measured roll gap, so that the actual roll gap and rolling table consistent. Adjust the rolling centerline with the optical centering device, and the center line of the rolling mill must be calibrated during the annual overhaul. </ Div>
Head and tail wall thickness uneven reason is the front of the tube cut slope, bending is too large, tube boring center is not easy to cause steel pipe head wall thickness uneven. Perforation elongation coefficient is too large, the roll speed is too high, rolling instability. Piercing machine throwing steel instability can easily lead to capillary tail wall thickness uneven. The measure is to check the quality of the tube, to prevent the front of the tube cutting slope, a large amount of pressure, change the hole or maintenance should be corrected centering hole. Using a lower punching speed to ensure the stability of the rolling and capillary wall thickness uniformity. When the roll speed is adjusted, the matching guide plate is also adjusted accordingly.