Method for realizing precision straightening of thin-wall seamless steel tubes by adopting six-roller straightener

Abstract

The invention discloses a method for realizing the precision straightening of thin-wall seamless steel tubes by adopting a six-roller straightener, aiming at providing a method for obtaining optimum technological parameters and producing thin-wall seamless steel tubes with high surface quality by calculating straightening press-down quantity and correcting press-down quantity, comparing the resultant force of straightening applied force and correcting applied force with and hertz contact force, and checking straightness accuracy and the diameter difference of long shafts and short shafts of an ellipse. The method comprises the following steps: confirming the press-down bending and straightening frequency and press-flat bending and correcting frequency; confirming the straightening press-down quantity, the straightening applied force, the correcting press-down quantity and the correcting applied force; working out the hertz contact force resulting in the sag deformation of the seamless steel tubes according to a hertz contact theory; comparing the hertz contact force with the resultant force of the straightening applied force and the correcting applied force; calculating straightness error according to the actual straightening press-down quantity from 1 to the last straightening; and calculating the corrected diameter difference of the long shafts of the ellipse and the diameter difference of the short shafts of the ellipse from 1 to the last correcting and comparing with a standard value.

Description

technical field [0001] The invention relates to a method for realizing precise straightening of thin-walled seamless steel pipes by adopting a six-roller straightening machine. Background technique [0002] Thin-walled seamless steel pipe, as a kind of economical section steel, has been increasing in production scale. However, the production methods of well-known domestic seamless steel pipe manufacturers are basically the direct introduction of existing foreign equipment and processes, which will inevitably lead to a lag in the theoretical research followed by production. [0003] In fact, due to the poor stability of the cross-sectional structure of thin-walled seamless steel pipes, its straightening and rolling production has its own characteristics. If the relevant parameters are not set properly, it is very easy to cause the phenomenon of sag on the surface of the pipe body during the straightening process, which directly affects the surface quality and dimensional acc...

AI Technical Summary

Problems solved by technology

However, since the phenomenon of cross-sectional distortion is not considered, the reduction amount is usually calculated by the material mechanics method-bending deflection calculation method, and the obtained straightening (or correction) reduction amount is sometimes too large, causing a large straightening force It will easily produce spiral indentation and surface depression on the surface of the steel pipe, and the qualified rate is low

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