Analysis of uneven and eccentric thickness of seamless steel pipe (1)
When the seamless steel pipe is used in production, the problem of uneven wall thickness and eccentricity of the steel pipe is sometimes encountered. What causes this? Can this phenomenon be avoided? Below we discuss the problem of uneven and eccentric thickness of seamless steel pipe.
First of all, there are roughly four reasons for the uneven wall thickness of seamless steel pipes produced by automatic tube rolling machines:
(1) The existence form and severity of the uneven wall thickness of perforated tube directly affect the existence form and severity of the uneven wall thickness of rolled steel tube.
(2) In the automatic pipe rolling machine, the wall thickness is uneven due to the bending of the top rod, so that the top head position deviates from the center of the pass, and the maximum wall thickness and minimum wall thickness positions on each cross section of the pipe and the pipe head are almost fixed; Therefore, reducing the residual curvature of the ejector rod and reducing the axial force of the ejector rod during the rolling process has a significant effect on reducing the wall thickness heterogeneity.
(3) The greater the amount of wall reduction, the more serious the uneven wall thickness of the pipe, the smaller the amount of wall reduction, the automatic tube rolling machine has the effect of reducing the uneven wall thickness of the perforated tube.
(2) The pass adjustment is not correct, and when the roll seam is uneven, the uneven wall thickness of the pipe will be aggravated.
