Sizing and rolling process of thick-walled seamless steel pipe by two-roller cross-rolling mill

Abstract

The invention discloses a technique for sizing thick-walled seamless steel tubes through a two-roller skew rolling mill. The sizing technique comprises the steps of (1) adjusting the milling roller distance of the two-roller skew rolling mill to enable the milling roller distance to be 1.01-1.05 times of the outer diameter of a finished steel tube, and adjusting the guide disk distance of the two-roller skew rolling mill to enable the guide disk distance to be 1.02-1.10 times of the roller distance; and (2) sleeving a crude tube on a sizing core rod of the two-roller skew rolling mill, and conducting sizing and rolling and obtaining the thick-walled seamless steel tubes under the action of milling rollers and guide disks. During sizing and rolling, the portion, in contact with the milling rollers, of the crude tube serves as a rolled section, and a gap is always reserved between the inner wall of the rolled section and the sizing core rod. According to the sizing technique, the cost of a sizing skew rolling mill is saved, only core rods with the appropriate diameters are needed, the producing cost is greatly saved, and the sale prospect is improved. Furthermore, the sized seamless steel tubes have the beneficial effects of being high in geometric dimension accuracy, good in straightness and free of crack. The invention further discloses a technique for rolling the thick-walled seamless steel tubes through the two-roller skew rolling mill.

Description

technical field [0001] The present invention relates to a sizing process, especially a sizing process for thick-walled seamless steel pipes using a two-roll cross-rolling mill. Rolling process of wall seamless steel pipe. Background technique [0002] Seamless steel pipe is a round, square or rectangular steel material with a hollow cross-section and no joints around it. At present, in the production of seamless steel pipes, the two-roll cross-rolling unit is an important production equipment. The technological process of the production equipment is: heating process-piercing process-wall reduction process of two-roll cross-rolling mill-sizing process of sizing machine . In the above process, the tube blank is heated to a temperature suitable for deformation through a heating furnace; the solid tube blank is pierced into a hollow capillary tube through a piercing machine; Waste pipe; the circumference of the waste pipe is sized by a sizing machine. [0003] Among them, su...

AI Technical Summary

Problems solved by technology

However, because the equipment adopts three-roller deformation, and there is no guide plate 3 to constrain the outer diameter of the deformation zone, the arc curvature of the cross-section of the waste pipe 4a changes greatly, and often due to repeated bending deformation, external folds and internal cracks are formed; in addition, the equipment is complicated , large investment, difficult to promote

[0006] To sum up, one of the advantages of the traditional two-roll cross-rolling unit is that it can quickly change specifications, which is especially suitable for meeting the needs of customers for small batches, multiple specifications, and fast delivery; but its applicable specification range is relatively narrow and cannot meet the specification range Production needs with wide changes and large batches

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