Specific Reasons And Measures For Uneven Thickness Of Thick-walled Seamless Steel Tubes

The uneven thickness of thick-walled seamless steel pipe is mainly manifested by uneven spiral wall, uneven wall thickness and thick and thin wall thickness of the head and tail.

The unevenness of the spiral thick-walled seamless steel pipe is caused by the unevenness of the center line of the piercing mill, the inclination of the two rolls, or the small amount of pressure before the head is too small, and the thickness of the steel pipe is generally uneven. It is spirally distributed. The first method is to adjust the center line of the punching machine so that the inclination angle of the two rolls is flat, and the rolling mill is adjusted according to the parameters given by the rolling table.

The reason why the linear wall thickness is uneven is that the height adjustment of the mandrel pre-wearing saddle is not suitable. When the mandrel is pre-weared, the capillary tube of one side is touched, so that the temperature drop of the capillary tube on the touch surface is too fast, and the wall thickness is uneven or even pulled. Concave defect. The gap of the continuous rolling roll is too small or too large. The center line error of the rolling mill. The unevenness of the single and double frame is uneven, which will form the ultra-thin (super thick) direction of the single steel frame and the extra thick in the double frame direction. (ultra-thin) linear symmetry error.

The first method is to adjust the height of the mandrel pre-wearing saddle and ensure that the mandrel and the capillary are centered. When replacing the hole type and rolling standard, the roll gap should be measured to make the actual roll gap and rolling. The watchmaking is consistent. The centering of the rolling is adjusted by the optical centering device. It is necessary to check the center line of the rolling mill during the annual overhaul.

The reason for the uneven wall thickness of the head and tail is that the front end of the tube blank is not inclined, the bending degree is too large, and the tube blank centering hole is not easy to form uneven thickness of the steel pipe head. The elongation coefficient is too large and the roll speed is too high. Unstable rolling. The hole casting machine is unstable and easy to form uneven thickness of the tail of the capillary.

The method is to check the quality of the tube blank, prevent the front end of the tube from being cut and the amount of pressing, and replace the hole type or the inspection should be proofed. Hole. Use a lower perforation speed to ensure the stability of the rolling and the uniformity of the wall thickness of the capillary. When the roll speed is adjusted, the matching guides are also adjusted accordingly.

A worker from a steel pipe company, which is located in China.