Method for producing seamless steel tube by combination of drawing and expanding and device thereof

Abstract

The invention provides a method for producing a seamless steel pipe by combining drawing and expanding, including: adopting a drawing power source, which is characterized in that an open type locking member is fixed and connected to a pipe orifice of a steel tube to be drawn, a detachable locking device is arranged on the open type locking member, when drawing, the detachable locking device locks the open type locking member and is connected to the drawing power source, under the action of the drawing power source, the detachable locking device is drew to draw the steel tube to be drawn, after the drawing, the detachable locking device loosens the open type locking member, the steel tube fixed and connected to the open type locking member enters an expanding process; because the pipe orifice of the steel tube is fixed and connected to the open type locking member, when expanding, the diameter expanding can be performed without removing the open type locking member, after expanding the detachable locking device is mounted on the open type locking member which is fixed and connected to the steel tube, the drawing process is repeated, thus the drawing and expanding are continuously cycled till the needed steel tube diameter.

Description

technical field [0001] The invention relates to a steel pipe production technology, in particular to a method suitable for producing seamless steel pipes in combination with drawing and diameter expansion. Background technique [0002] In the production of medium and large-sized steel pipes, the diameter-expanding process is generally adopted, but since the wall thickness of the raw material pipe cannot be completely consistent at all points on the circumference, there is an eccentricity problem, and the unevenness of the thickness is distributed in an S shape making it difficult to remove this defect. Drawing can improve the eccentricity of the steel pipe, so that the thick points distributed in the S shape can be squeezed and flattened, while the diameter expansion intensifies the eccentricity of the steel pipe, making the metal structure of the steel pipe loose. In order to improve this situation, many domestic manufacturers currently use a combination of drawing and dia...

AI Technical Summary

Problems solved by technology

Therefore, in the prior art, if the process of combining drawing and diameter expansion is to be realized, the columnar steel block used as the drawing head of the steel pipe must be welded and then cut for many times, which is time-consuming, material-intensive and labor-intensive. operation, which also greatly increases the production cost of steel pipes. Under the condition of market economy, the current drawing and diameter expansion process has to be used in making some thin-walled large-diameter steel pipes. Usually, manufacturers cannot be produced by this process

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